The document summarizes key aspects of the human eye and optics. It describes how light stimulates vision and defines the electromagnetic spectrum. It then details the basic anatomy of the eye, including that it is divided into two chambers filled with aqueous and vitreous humor. Optics are discussed next, specifically how light enters through the cornea and pupil, is focused by the lens, and forms an image on the retina. Common refractive errors like myopia and hyperopia are also summarized. Finally, Gullstrand's schematic eye model is introduced as a simplified representation of the optical components and parameters of the typical human eye.

1. OPTI C’S OF HUMAN EYE
HARSH JAIN
B-Optometry

2. Light
• Light is a form of energy whose interaction with retina
gives the sensation of sight.
• The stimulus for vision is light energy-a small part of
the spectrum of electromagnetic radiation.
• Other organisms are sensitive to other parts of the
electromagnetic spectrum.

3. Light
• The wavelength of light determines the hue or
color that we perceive.

4. The Eye
• The eye possess a circular shape
• Eyeball is often referred to as a globe.
• The eye is held in position and moved by a series of six
extraocular muscles.

6. The Eye
• The eye is divided into Two chambers
 Anterior chamber:
• The region of the eye between the cornea and the
lens that contains aqueous humor.
 Posterior Chamber:
• Rear section of the eye from the back of the lens
to the retina.
• Filled with vitreous humor.

7. The Eye

8. The Eye/Optics
• The stimulus for vision is light.
• For us to perceive objects and patterns, the eye
must take light reflected of the surface of the
object or pattern, and project it onto the retina.
• The light must be refracted and focused on the
retina

9. The Eye/Optics

10. The Eye/Optics
Cornea:
• Carries out the initial
bending of light.
• The primary refractive
surface.
Pupil:
• An opening in the front of
the eye through which light
passes.

11. The Eye/Optics
Iris:
• A series of muscles that control the size of the pupil,
and in turn, controls the amount of light entering
the eye.

12. The Eye/Optics
Lens:
• A transparent biconvex
structure that refracts
light.
• Changes its thickness
(accommodates) to focus
objects at different
distances.

13. The Eye/Optics
Distant Objects:
Ciliary muscles Contract,
lens is relatively Flat.
Near Objects:
• Ciliary muscles Relax,
lens is Steeper.

14. The Eye/Optics
• Suspended by the zonule fibers which are
attached to the ciliary body/muscles.

15. ERROR’S
MYOPIA
FORMING FOCUS INFRONT OF RETINA, WHEN
ACCOMMODATION AT REST.
HYPERMETROPIA
FORMING FOCUS BEHIND THE RETINA,WHEN
ACCOMMODATION AT REST.
ASTIGMATISM
FORMING TWO LINE FOCI ,EITHER INFRONT {OR}
BEHIND THE RETINA.

16. DIAGRAM

17. GULLSTRAND’S SCHEMATIC EYE
HARSH JAIN
1st Year B-Optom
B.V.P.D.M.C

18. GULLSTRAND SCHEMATIC EYE
• The refractive state of the eye is given by the value’s of the
individual refractive component’s of the eye and there
relationship’s with one-another
• The value’s of refractive component’s are determine by
their radia of curvature {cornea & lens} & their indice’s of
refraction.
• For a healthy eye, the refractive indice’s show little
variation’s from 1eye to another eye ; BUT the radia of
curvature of the cornea and lens as well as anterior
chamber depth and the axial length of the eye can very
widely from 1 eye to another eye.

19. GULLSTRAND SCHEMATIC EYE
• The refractive component of the eye & it’s focal point’s principle
point’s & nodal point’s are generally characterized in term’s of a
schematic eye.
• This schematic eyes are useful in performing no.of calculation’s
related to optic’s of eye & are practically useful in calculation
involving magnification.
• Although, a large no.of schematic eye’s have being design, the
best known & most detailed is the exact schematic eye, design
by Gull-Strand’s.

20. FORM’S PART’S EXACT EYE SIMPLIFIED EYE
INDICE’S Cornea 1.376 -----
Aqueous Humour 1.336 1.336
Len’s Cortex 1.386 -----
Len’s Nuclues 1.406 1.413
Viterous Humour 1.336 1.336
POSITION Cornea Anterior 0 0
Cornea Posterior 0.5mm -----
Len’s Anterior 3.6mm 3.6mm
Len’s Posterior 7.2mm 7.2mm

21. FORM’S PART’S EXACT EYE SIMPLIFIED EYE
RADIA OF Cornea Anterior 7.7mm 7.8mm
CURVATURE Cornea Posterior 6.8mm -----
Len’s Anterior 10.0mm 10.0mm
Len’s Posterior -6.0mm -6.0mm
REFRACTIVE Cornea + 43.05 D + 42.74 D
POWER Len’s + 19.11 D + 21.76 D
TOTAL + 5 8 . 6 4 D + 6 0 . 4 8 D
FOCAL POINT Anterior -15.70mm -14.99mm
Posterior 24.38mm 23.90mm
AXIAL LENGHT Complete 24mm 23.90mm

22. Theory & Practise Of Optic’s & Refraction
–A.K Khurana
Anatomy & Physiology Of Eye –A.K
Khurana
Duke Elder’s Practise of Refraction.