Sclera: a tough white layer ofSclera: a tough white layer of
connective tissue that covers allconnective tissue that cove...
Choroid: thin, pigmented layer liningChoroid: thin, pigmented layer lining
the interior surface of the sclera.the interio...
The lens and ciliary body divide the eyeThe lens and ciliary body divide the eye
into two cavities.into two cavities.
Th...
Accommodation isAccommodation is
the focusing ofthe focusing of
light in the retina.light in the retina.
Mammals focus b...
Photoreceptors of the retina.
rod cells - light sensitive but do not
distinguish colors.
cone cells - not as light sens...
Vision is your ability to see.Vision is your ability to see.
Vision involves the eye and the brainVision involves the eye ...
The eye is one of your senseThe eye is one of your sense
organs.organs.
The eye is made of the irisThe eye is made of the ...
The colored part of the eye isThe colored part of the eye is
the iris.the iris.
The black part of the eye is theThe black ...
From the moment you wake up in the morningFrom the moment you wake up in the morning
to the time you go to sleep at night...
Take a moment to locate an objectTake a moment to locate an object
around you. Do you know how youaround you. Do you know...
Your lens in your eyes change sizeYour lens in your eyes change size
all the time. When you look atall the time. When you...
Rods and cones are special cells that process light.Rods and cones are special cells that process light.
Rods and cones ar...
When you see images, they turn upsideWhen you see images, they turn upside
down when they hit the retina. So yourdown whe...
There are the six small muscles that move each eye from side to side,There are the six small muscles that move each eye fr...
 Because the eye is such an important andBecause the eye is such an important and
complex part of our body, we have manyc...
NearsightedNearsighted
Not all people have perfect vision.Not all people have perfect vision.
People who can see things up...
Whether a person is nearsighted or farsighted, glasses or contactsWhether a person is nearsighted or farsighted, glasses o...
Eye Fun FactsEye Fun Facts
• A chameleon's eyes can look inA chameleon's eyes can look in
opposite directions at the sameopposite directions at the s...
By the end of thisBy the end of this
presentation you will be ablepresentation you will be able
to:to:
Recognize majorRe...
The eye allows us to see and interpret theThe eye allows us to see and interpret the
shapes, colors and dimensions of obj...
When you look at any objectWhen you look at any object
 Light waves from that object enter theLight waves from that objec...
 Light waves are bent (converged) first by theLight waves are bent (converged) first by the
cornea, then even more so by ...
The light impulses are changed intoThe light impulses are changed into
electrical signals, then sent throughelectrical si...
Extra ocular MusclesExtra ocular Muscles
All of the extra ocular muscles, withAll of the extra ocular muscles, with
the exception of the inferior oblique,the exce...
 The superior oblique muscle isThe superior oblique muscle is
different from the others, becausedifferent from the others...
 The primary muscle that movesThe primary muscle that moves
an eye in a given direction isan eye in a given direction is
...
Cardinal positions of gazeCardinal positions of gaze
Up/rightUp/right
Up/leftUp/left
RightRight
LeftLeft
Down/rightD...
 A “vergence” or “disconjugate”A “vergence” or “disconjugate”
movement involvesmovement involves
simultaneous movement of...
StrabismusStrabismus
Usually when we see an object, theUsually when we see an object, the
lines of sight are both eyesline...
Strabismus,Strabismus,
(cont’d)(cont’d)
With strabismus, while one eye isWith strabismus, while one eye is
fixating on a p...
Diabetic RetinopathyDiabetic Retinopathy
This is a complication of diabetesThis is a complication of diabetes
mellitus in ...
42
 A cataract is a clouding of the eye's naturalA cataract is a clouding of the eye's natural
lens, which lies behind th...
Researchers are identifyingResearchers are identifying
factors that may cause cataractsfactors that may cause cataracts
s...
GlaucomaGlaucoma
Glaucoma represents injury to the optic nerveGlaucoma represents injury to the optic nerve
secondary to ...
Glaucoma (cont’d)Glaucoma (cont’d)
 Most patients with glaucoma do haveMost patients with glaucoma do have
elevated intra...
Miscellaneous tidbits about the eyesMiscellaneous tidbits about the eyes
Anterior chamber – refers to the fluid filledAnt...
Miscellaneous tidbits about the eyesMiscellaneous tidbits about the eyes
(cont’d)(cont’d)
A newborn’s eyeball is about 18...
48
1.1. How do you see?How do you see?
Rays of light pass through theRays of light pass through the
pupil in your eye , which...
Your pupil is the black circle in theYour pupil is the black circle in the
middle of the coloured part of yourmiddle of th...
Your eyes constantly make tears,Your eyes constantly make tears,
which stop your eyes drying out.which stop your eyes dryi...
The colour of your eyes dependsThe colour of your eyes depends
on the amount of pigment thaton the amount of pigment that
...
A blind person who is colour cannot tellA blind person who is colour cannot tell
the difference between certain colours,th...
Have you noticed that animals eye shine in theHave you noticed that animals eye shine in the
dark? This is because their e...
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
Chris sci project on eyes
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  • Track x – xxx day – 0000-0000
  • Track x – xxx day – 0000-0000 START WITH THIS: The human eye is the organ which gives us the sense of sight, allowing us to learn more about the surrounding world than we do with any of the other four senses. We use our eyes in almost every activity we perform, whether reading, working, watching television, writing , driving and in countless other ways. Most people would probably agree that sight is more valued than all the rest of their senses.
  • Track x – xxx day – 0000-0000
  • Track x – xxx day – 0000-0000 If you think of your eye as a camera , the retina would be like the film inside a camera that registers the tiny photons of light with produces the picture.
  • Track x – xxx day – 0000-0000 In these layers of the retina, light impulses are changed into electrical signals and then sent through the optic nerve
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  • Track x – xxx day – 0000-0000 Stay on this page All of the extraocular muscles, with the exception of the inferior oblique form a “cone” within the bony orbit. The apex of the cone is in the posterior aspect of the orbit, while the base of the cone is the attachment of the muscles around the midline of the eye. This conic structure is referred to as the “ annulus of Zinn and within this cone runs the Optic nerve (cranial nerve H). Within the optic nerve are the ophthalmic artery and the ophthalmic vein.
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  • Track x – xxx day – 0000-0000 Macula is in the retina
  • Track x – xxx day – 0000-0000 At this point, we’re not talking specific diseases of the eye, but the “disorders” of the muscles is a good transitions to eye disease. Let’s take a look at what disease affects which part of the eye we just learned about!
  • Track x – xxx day – 0000-0000
  • Track x – xxx day – 0000-0000 The lens works much like a camera lens, focusing light onto the retina at the back of the eye. The lens also adjusts the eye's focus, letting us see things clearly both up close and far away.
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  • Chris sci project on eyes

    1. 1. Sclera: a tough white layer ofSclera: a tough white layer of connective tissue that covers allconnective tissue that covers all of the eyeball except the cornea.of the eyeball except the cornea. Conjunctiva: external cover ofConjunctiva: external cover of the sclera — keeps the eyethe sclera — keeps the eye moist.moist. Cornea: transparent covering ofCornea: transparent covering of the front of the eye.the front of the eye. Allows for the passage of lightAllows for the passage of light into the eye and functions as ainto the eye and functions as a fixed lens.fixed lens.
    2. 2. Choroid: thin, pigmented layer liningChoroid: thin, pigmented layer lining the interior surface of the sclera.the interior surface of the sclera. Prevents light rays from scatteringPrevents light rays from scattering and distorting the image.and distorting the image. o Interiorly it forms the iris.Interiorly it forms the iris. The iris regulates the sizeThe iris regulates the size of the pupil.of the pupil. Retina: lines the interior surface of theRetina: lines the interior surface of the choroid.choroid. Contains photo receptors.Contains photo receptors. Except at the optic disk (where theExcept at the optic disk (where the optic nerve attaches).optic nerve attaches).
    3. 3. The lens and ciliary body divide the eyeThe lens and ciliary body divide the eye into two cavities.into two cavities. The anterior cavity is filled withThe anterior cavity is filled with aqueous humor produced by theaqueous humor produced by the ciliary body.ciliary body. The posterior cavity is filled withThe posterior cavity is filled with vitreous humor.vitreous humor. The lens, the aqueous humor, and theThe lens, the aqueous humor, and the vitreous humor all play a role invitreous humor all play a role in focusing light onto the retina.focusing light onto the retina.
    4. 4. Accommodation isAccommodation is the focusing ofthe focusing of light in the retina.light in the retina. Mammals focus byMammals focus by changing the shapechanging the shape of the lens.of the lens. The lens isThe lens is flattened forflattened for distant objects.distant objects. The lens isThe lens is rounded for nearrounded for near objects.objects.
    5. 5. Photoreceptors of the retina. rod cells - light sensitive but do not distinguish colors. cone cells - not as light sensitive as rods but provide color vision Most highly concentrated on the fovea – an area of the retina that lacks rods.
    6. 6. Vision is your ability to see.Vision is your ability to see. Vision involves the eye and the brainVision involves the eye and the brain.
    7. 7. The eye is one of your senseThe eye is one of your sense organs.organs. The eye is made of the irisThe eye is made of the iris and the pupil.and the pupil. The eye gathers pictures andThe eye gathers pictures and sends them to the brain.sends them to the brain.
    8. 8. The colored part of the eye isThe colored part of the eye is the iris.the iris. The black part of the eye is theThe black part of the eye is the pupil.pupil. The pupil becomesThe pupil becomes larger and smallerlarger and smaller as it controls theas it controls the light coming into thelight coming into the eyeeye.. IrisIris PupilPupil
    9. 9. From the moment you wake up in the morningFrom the moment you wake up in the morning to the time you go to sleep at night, your eyesto the time you go to sleep at night, your eyes are acting like a video camera. Everything youare acting like a video camera. Everything you look at is then sent to your brain forlook at is then sent to your brain for processing and storage much like a videoprocessing and storage much like a video cassette. This is a very simplified explanation,cassette. This is a very simplified explanation, but as you read on, you will discover why thebut as you read on, you will discover why the sense of sight is actually considered the mostsense of sight is actually considered the most complex of the five senses.complex of the five senses.
    10. 10. Take a moment to locate an objectTake a moment to locate an object around you. Do you know how youaround you. Do you know how you are able to see it? Would you believeare able to see it? Would you believe that what you are actually seeing arethat what you are actually seeing are beams of light bouncing off of thebeams of light bouncing off of the object and into your eyes? It is hardobject and into your eyes? It is hard to believe, but it is true.to believe, but it is true. The light rays enter the eye throughThe light rays enter the eye through the cornea, which is a thick,the cornea, which is a thick, transparent protective layer on thetransparent protective layer on the surface of your eye. Then the lightsurface of your eye. Then the light rays pass through the pupil (the darkrays pass through the pupil (the dark circle in the centre of your eye) andcircle in the centre of your eye) and into the lens.into the lens.
    11. 11. Your lens in your eyes change sizeYour lens in your eyes change size all the time. When you look atall the time. When you look at objects real close up, the lens getsobjects real close up, the lens gets thicker. If you look at objects farthicker. If you look at objects far away, it gets thinner. It does this toaway, it gets thinner. It does this to help you focus the correct image onhelp you focus the correct image on the retina.the retina. After light passes through the lens itAfter light passes through the lens it shines through the vitreous humor toshines through the vitreous humor to the back of the eye where it hits thethe back of the eye where it hits the retina. The retina takes the light andretina. The retina takes the light and changes it into nerve impulse so thechanges it into nerve impulse so the brain can understand what the eyebrain can understand what the eye sees. It sends the message to the
    12. 12. Rods and cones are special cells that process light.Rods and cones are special cells that process light. Rods and cones are extremely small. In fact, there areRods and cones are extremely small. In fact, there are about 120 million rods and 7 million cones in each eye!about 120 million rods and 7 million cones in each eye! Rods help us see black and white and shades of grey.Rods help us see black and white and shades of grey. Cones help us see color. You have three kinds of cones are -Cones help us see color. You have three kinds of cones are - red, green, and blue. These cones work together to help usred, green, and blue. These cones work together to help us see millions of colors.see millions of colors.
    13. 13. When you see images, they turn upsideWhen you see images, they turn upside down when they hit the retina. So yourdown when they hit the retina. So your brain sees everything in the worldbrain sees everything in the world upside down. Your brain basically flipsupside down. Your brain basically flips everything around so it is right side upeverything around so it is right side up again.again.
    14. 14. There are the six small muscles that move each eye from side to side,There are the six small muscles that move each eye from side to side, up and down and on the slant. When these muscles don't workup and down and on the slant. When these muscles don't work together, it can affect vision. One condition that can arise when thesetogether, it can affect vision. One condition that can arise when these muscles don't work together is “lazy eye”, a condition that affectsmuscles don't work together is “lazy eye”, a condition that affects about 5% of children and arises when the eye muscles don't workabout 5% of children and arises when the eye muscles don't work together properly. This leads to "lazy eye," in which one eye takestogether properly. This leads to "lazy eye," in which one eye takes over all the vision duties. A defining characteristic of these tinyover all the vision duties. A defining characteristic of these tiny muscles is that they are nearly always moving, even during sleep. Inmuscles is that they are nearly always moving, even during sleep. In fact, even when "staring" at a fixed object, the eyes keep moving overfact, even when "staring" at a fixed object, the eyes keep moving over the image. Although these muscles are very small, they use a lot ofthe image. Although these muscles are very small, they use a lot of
    15. 15.  Because the eye is such an important andBecause the eye is such an important and complex part of our body, we have manycomplex part of our body, we have many features which protect the eye.features which protect the eye. The eyebrowsThe eyebrows are the strips of hair aboveare the strips of hair above your eyes which prevent sweat from runningyour eyes which prevent sweat from running into them.into them. EyelashesEyelashes help keep the eye clean byhelp keep the eye clean by collecting small dirt and dust particlescollecting small dirt and dust particles floating through the air. The eyelashesfloating through the air. The eyelashes also protect the eye from the sun's andalso protect the eye from the sun's and other light's glare. The eyelids sweep dirtother light's glare. The eyelids sweep dirt from the surface of the eye. The eyelid alsofrom the surface of the eye. The eyelid also protects the eye from injury.protects the eye from injury. TearsTears are sterile drops of clean waterare sterile drops of clean water which constantly bathe the front of the eye,which constantly bathe the front of the eye, keeping it clean and moist.keeping it clean and moist.
    16. 16. NearsightedNearsighted Not all people have perfect vision.Not all people have perfect vision. People who can see things up close, but not farPeople who can see things up close, but not far away are considered to be nearsighted. Thisaway are considered to be nearsighted. This happens when the light entering the eye focuseshappens when the light entering the eye focuses on a point in front of the retina.on a point in front of the retina.
    17. 17. Whether a person is nearsighted or farsighted, glasses or contactsWhether a person is nearsighted or farsighted, glasses or contacts help that person to see things much more clearly!help that person to see things much more clearly!
    18. 18. Eye Fun FactsEye Fun Facts
    19. 19. • A chameleon's eyes can look inA chameleon's eyes can look in opposite directions at the sameopposite directions at the same time.time. • A newborn baby sees the worldA newborn baby sees the world upside down because it takesupside down because it takes some time for the baby's brain tosome time for the baby's brain to learn to turn the picture right-learn to turn the picture right- side up.side up. • One in every twelve males isOne in every twelve males is colour blindcolour blind A male human can see over 1A male human can see over 1 million coloursmillion colours Whereas a female human can seeWhereas a female human can see
    20. 20. By the end of thisBy the end of this presentation you will be ablepresentation you will be able to:to: Recognize majorRecognize major components of the eyecomponents of the eye Have a basic understandingHave a basic understanding of how the eye worksof how the eye works Understand how eye diseaseUnderstand how eye disease affects the components ofaffects the components of
    21. 21. The eye allows us to see and interpret theThe eye allows us to see and interpret the shapes, colors and dimensions of objects inshapes, colors and dimensions of objects in the world by processing the light theythe world by processing the light they reflect or emitreflect or emit  The eye is able to see in bright or dim light,The eye is able to see in bright or dim light, but it cannot see objects when light isbut it cannot see objects when light is
    22. 22. When you look at any objectWhen you look at any object  Light waves from that object enter theLight waves from that object enter the eye first through the cornea, which iseye first through the cornea, which is the clear dome at the front of the eyethe clear dome at the front of the eye Light waves progress through theLight waves progress through the pupil, the circular opening in thepupil, the circular opening in the center of the colored iriscenter of the colored iris Immediately behind the iris (andImmediately behind the iris (and pupil) is the crystalline lens, andpupil) is the crystalline lens, and light passes through that also.light passes through that also.
    23. 23.  Light waves are bent (converged) first by theLight waves are bent (converged) first by the cornea, then even more so by the crystallinecornea, then even more so by the crystalline lens, to a nodal point which is immediatelylens, to a nodal point which is immediately behind the lensbehind the lens At the nodal point, the light waves (image)At the nodal point, the light waves (image) become reversed (turned backwards) andbecome reversed (turned backwards) and inverted (turned upside down)inverted (turned upside down) Light waves continue through the vitreousLight waves continue through the vitreous humor, the clear gel that makes up abouthumor, the clear gel that makes up about 80% of the eye’s volume, and then back to a80% of the eye’s volume, and then back to a clear focus on the retina behind the vitreousclear focus on the retina behind the vitreous The small, central area of the retina is theThe small, central area of the retina is the macula; it provides the best vision of anymacula; it provides the best vision of any location in the retinalocation in the retina
    24. 24. The light impulses are changed intoThe light impulses are changed into electrical signals, then sent throughelectrical signals, then sent through the optic nerve along the visualthe optic nerve along the visual pathway to the occipital cortex, orpathway to the occipital cortex, or posterior (back), of the brainposterior (back), of the brain This is where the electrical signalsThis is where the electrical signals are seen by the brain as a visualare seen by the brain as a visual imageimage When light entering the eye is brightWhen light entering the eye is bright enough, the pupils will get smallerenough, the pupils will get smaller (constrict) due to pupillary light(constrict) due to pupillary light
    25. 25. Extra ocular MusclesExtra ocular Muscles
    26. 26. All of the extra ocular muscles, withAll of the extra ocular muscles, with the exception of the inferior oblique,the exception of the inferior oblique, form a “cone” within the bony orbitform a “cone” within the bony orbit  The apex of the cone is in the posteriorThe apex of the cone is in the posterior aspect (back) of the orbit, while theaspect (back) of the orbit, while the base of the cone is the attachment of thebase of the cone is the attachment of the muscles around the midline of the eye.muscles around the midline of the eye. This conic structure is referred to as theThis conic structure is referred to as the “annulus of Zinn,” and within this cone“annulus of Zinn,” and within this cone runs the Optic nerve (cranial nerve H)runs the Optic nerve (cranial nerve H)  Within the optic nerve are theWithin the optic nerve are the ophthalmic artery and the ophthalmicophthalmic artery and the ophthalmic veinvein
    27. 27.  The superior oblique muscle isThe superior oblique muscle is different from the others, becausedifferent from the others, because before it attaches to the eye, it passesbefore it attaches to the eye, it passes through a ring-like tendon, thethrough a ring-like tendon, the trochlea, which acts like a pulley introchlea, which acts like a pulley in the nasal portion of the orbitthe nasal portion of the orbit  The inferior oblique muscle (not aThe inferior oblique muscle (not a member of the annulus of Zinn)member of the annulus of Zinn) arises from the lacrimal fossa in thearises from the lacrimal fossa in the nasal portion of the bony orbit andnasal portion of the bony orbit and attaches to the inferior portion of theattaches to the inferior portion of the
    28. 28.  The primary muscle that movesThe primary muscle that moves an eye in a given direction isan eye in a given direction is known as the agonistknown as the agonist  A muscle in the same eye thatA muscle in the same eye that moves the eye in the samemoves the eye in the same direction as the agonist is knowndirection as the agonist is known as a synergistas a synergist  A muscle in the same eye thatA muscle in the same eye that moves the eye in the oppositemoves the eye in the opposite direction of the agonist is thedirection of the agonist is the antagonistantagonist
    29. 29. Cardinal positions of gazeCardinal positions of gaze Up/rightUp/right Up/leftUp/left RightRight LeftLeft Down/rightDown/right Down/leftDown/left  In each position of gaze, one muscleIn each position of gaze, one muscle of each eye is the primary mover ofof each eye is the primary mover of that eye, and is “yoked” to thethat eye, and is “yoked” to the primary mover of the other eyeprimary mover of the other eye
    30. 30.  A “vergence” or “disconjugate”A “vergence” or “disconjugate” movement involvesmovement involves simultaneous movement of bothsimultaneous movement of both eyes in the oppositeeyes in the opposite directionsdirections There are two principal vergenceThere are two principal vergence movementsmovements Convergence – both eyesConvergence – both eyes moving nasally or inwardmoving nasally or inward Divergence – both eyes movingDivergence – both eyes moving temporally or upwardtemporally or upward
    31. 31. StrabismusStrabismus Usually when we see an object, theUsually when we see an object, the lines of sight are both eyeslines of sight are both eyes intersecting at the object, or both eyesintersecting at the object, or both eyes are pointing at the object being viewed.are pointing at the object being viewed. An image of the object is focusedAn image of the object is focused upon the macula of each eye and theupon the macula of each eye and the brain merges the two retinal imagesbrain merges the two retinal images into oneinto one When there is an extra ocular muscleWhen there is an extra ocular muscle imbalance, one eye is not aligned withimbalance, one eye is not aligned with the other eye, which results in athe other eye, which results in a
    32. 32. Strabismus,Strabismus, (cont’d)(cont’d) With strabismus, while one eye isWith strabismus, while one eye is fixating on a particular object, thefixating on a particular object, the other eye is turned in anotherother eye is turned in another direction, either inward (cross-eyed),direction, either inward (cross-eyed), outward (wall-eyed), upward, oroutward (wall-eyed), upward, or downwarddownward As a result, the person eitherAs a result, the person either experiences “diplopia” (doubleexperiences “diplopia” (double vision) or the brain learns to turnvision) or the brain learns to turn off (suppress) the image of theoff (suppress) the image of the strabismic eye to maintain singlestrabismic eye to maintain single visionvision
    33. 33. Diabetic RetinopathyDiabetic Retinopathy This is a complication of diabetesThis is a complication of diabetes mellitus in which long-term exposuremellitus in which long-term exposure to high glucose levels in the bloodto high glucose levels in the blood has damaged retinal blood vessels.has damaged retinal blood vessels. This results in new growth ofThis results in new growth of abnormal blood vessels, fluidabnormal blood vessels, fluid buildup in the macula (macularbuildup in the macula (macular edema), inadequate blood supply toedema), inadequate blood supply to the retina and possibly blood andthe retina and possibly blood and fluid leakage into the retina and thefluid leakage into the retina and the
    34. 34. 42  A cataract is a clouding of the eye's naturalA cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupillens, which lies behind the iris and the pupil  The lens is mostly made of water and protein.The lens is mostly made of water and protein. The protein is arranged in a precise way thatThe protein is arranged in a precise way that keeps the lens clear and lets light passkeeps the lens clear and lets light pass through it. But as we age, some of the proteinthrough it. But as we age, some of the protein may clump together and start to cloud amay clump together and start to cloud a small area of the lens. This is a cataract, andsmall area of the lens. This is a cataract, and over time, it may grow larger and cloud moreover time, it may grow larger and cloud more of the lens, making it harder to seeof the lens, making it harder to see
    35. 35. Researchers are identifyingResearchers are identifying factors that may cause cataractsfactors that may cause cataracts such as:such as: People with diabetesPeople with diabetes Users of steroids, diuretics,Users of steroids, diuretics, and major tranquilizersand major tranquilizers Users of a lot of saltUsers of a lot of salt Cigarette smokeCigarette smoke Air pollutionAir pollution Heavy alcohol consumptionHeavy alcohol consumption
    36. 36. GlaucomaGlaucoma Glaucoma represents injury to the optic nerveGlaucoma represents injury to the optic nerve secondary to elevated pressure inside the eye.secondary to elevated pressure inside the eye. However, there are exceptions to thisHowever, there are exceptions to this definitiondefinition Some patients with sustained high intra-Some patients with sustained high intra- ocular pressure never develop any of the signsocular pressure never develop any of the signs of optic nerve damage and therefore, do notof optic nerve damage and therefore, do not truly have glaucoma. These patients are saidtruly have glaucoma. These patients are said to have ocular hypertensionto have ocular hypertension Other patients may progressively lose visionOther patients may progressively lose vision and become blind, even though they neverand become blind, even though they never exhibit "high" eye pressures. These patientsexhibit "high" eye pressures. These patients
    37. 37. Glaucoma (cont’d)Glaucoma (cont’d)  Most patients with glaucoma do haveMost patients with glaucoma do have elevated intraocular pressure. Alongelevated intraocular pressure. Along with the eye pressure, other parameterswith the eye pressure, other parameters are evaluated in the search forare evaluated in the search for glaucoma, such as peripheral vision,glaucoma, such as peripheral vision, visual contrast sensitivity, optic nervevisual contrast sensitivity, optic nerve cupping (a hollowing out of the centercupping (a hollowing out of the center of the optic nerve head in the back ofof the optic nerve head in the back of the eye), and gonioscopy (visualizingthe eye), and gonioscopy (visualizing the anatomy of the filtering angle ofthe anatomy of the filtering angle of the eye, where the cornea and the iristhe eye, where the cornea and the iris
    38. 38. Miscellaneous tidbits about the eyesMiscellaneous tidbits about the eyes Anterior chamber – refers to the fluid filledAnterior chamber – refers to the fluid filled (aqueous humor) space between the cornea and(aqueous humor) space between the cornea and the iris/pupilthe iris/pupil Posterior chamber – refers to the fluid filledPosterior chamber – refers to the fluid filled (aqueous humor) ring-shaped space between(aqueous humor) ring-shaped space between the iris/pupil and the lens and ciliary bodythe iris/pupil and the lens and ciliary body Anterior segment – refers to the intraocularAnterior segment – refers to the intraocular portion of the eyeball and holds the anteriorportion of the eyeball and holds the anterior and posterior chambers of the eyeand posterior chambers of the eye Posterior segment – refers to the largePosterior segment – refers to the large vitreous-filled space between the retina andvitreous-filled space between the retina and the lens and where the optic nerve comes intothe lens and where the optic nerve comes into
    39. 39. Miscellaneous tidbits about the eyesMiscellaneous tidbits about the eyes (cont’d)(cont’d) A newborn’s eyeball is about 18A newborn’s eyeball is about 18 millimeters in diameter, from front to back.millimeters in diameter, from front to back. It grows gradually to a length ofIt grows gradually to a length of approximately 24-25 millimeters (aboutapproximately 24-25 millimeters (about 1”), or just smaller than a 1 1/2” ping pong1”), or just smaller than a 1 1/2” ping pong ball!ball!  CPT codes in the 60,000 series are dividedCPT codes in the 60,000 series are divided by the anatomical location of eitherby the anatomical location of either Anterior segmentAnterior segment Posterior segmentPosterior segment Ocular adenexaOcular adenexa
    40. 40. 48
    41. 41. 1.1. How do you see?How do you see? Rays of light pass through theRays of light pass through the pupil in your eye , which is like apupil in your eye , which is like a small hole. Behind each pupil is asmall hole. Behind each pupil is a lens which bends light so that itlens which bends light so that it shines on an area at the back ofshines on an area at the back of your eye called the retina. Thisyour eye called the retina. This makes an upside down picture onmakes an upside down picture on the retina of what you are seeingthe retina of what you are seeing The optic nerves in your eyes sendThe optic nerves in your eyes send
    42. 42. Your pupil is the black circle in theYour pupil is the black circle in the middle of the coloured part of yourmiddle of the coloured part of your eye. It is actually a hole in your eyeeye. It is actually a hole in your eye that lets light in. Your eyes work justthat lets light in. Your eyes work just like a camera, when it is bright yourlike a camera, when it is bright your eyes don't need to let so much light ineyes don't need to let so much light in for you to see so the muscles of thefor you to see so the muscles of the iris {the coloured part of your eye}iris {the coloured part of your eye} contract making the pupil holecontract making the pupil hole smaller. In light the iris expands tosmaller. In light the iris expands to make the pupil as large as possiblemake the pupil as large as possible to allow all the available light toto allow all the available light to enter your eye.enter your eye.
    43. 43. Your eyes constantly make tears,Your eyes constantly make tears, which stop your eyes drying out.which stop your eyes drying out. Tears contain proteins that killTears contain proteins that kill germs, helping prevent infectionsgerms, helping prevent infections in your eyes. You blink aboutin your eyes. You blink about fifteen times every minute,fifteen times every minute, spreading the tears across yourspreading the tears across your eyes. Extra tears fluid drainseyes. Extra tears fluid drains through a small tube into yourthrough a small tube into your nose, which is why your nosenose, which is why your nose also runs when your water or youalso runs when your water or you
    44. 44. The colour of your eyes dependsThe colour of your eyes depends on the amount of pigment thaton the amount of pigment that is in the iris. Brown eyes have ais in the iris. Brown eyes have a lot of pigment, while blue eyeslot of pigment, while blue eyes have a little. You inherited yourhave a little. You inherited your eye colour from your parents.eye colour from your parents. The most common eye colour isThe most common eye colour is brown. If one of your parentsbrown. If one of your parents has brown eyes and the otherhas brown eyes and the other has blue eyes, your eyes willhas blue eyes, your eyes will
    45. 45. A blind person who is colour cannot tellA blind person who is colour cannot tell the difference between certain colours,the difference between certain colours, most often red and green. This is amost often red and green. This is a condition which is inherited and about tencondition which is inherited and about ten percent of males have it. It is very rare inpercent of males have it. It is very rare in females.females. 6.6. How do my eyes help me see?How do my eyes help me see? Each of your eyes is a ball. At the front,Each of your eyes is a ball. At the front, there’s a black whole called the pupil,there’s a black whole called the pupil, which lets in light. Behind the pupil is awhich lets in light. Behind the pupil is a lens that help you to see things close tolens that help you to see things close to or far away. The optic nerve carriesor far away. The optic nerve carries messages about what you see to yourmessages about what you see to your
    46. 46. Have you noticed that animals eye shine in theHave you noticed that animals eye shine in the dark? This is because their eyes reflect light back,dark? This is because their eyes reflect light back, so if you shine a light on them, the reflection canso if you shine a light on them, the reflection can be seen in the dark. A man called Edwin Shaw,be seen in the dark. A man called Edwin Shaw, from England, noticed this and made “cat’s eyes”from England, noticed this and made “cat’s eyes” From glass which were set in rubber and placed inFrom glass which were set in rubber and placed in the middle of roads helping driver’s stay on thethe middle of roads helping driver’s stay on the road in the dark.road in the dark. Now it’s time forNow it’s time for some eyesome eyeMAGICMAGIC
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