The eye is a spheroid structure around the size of a ping pong ball that functions to distinguish light, dark, shape, color, brightness and distance. It includes structures like the eyelids, conjunctiva, cornea, iris, pupil, lens, vitreous humor, retina, blood vessels and optic nerve. The retina contains light-sensitive photoreceptor cells called rods and cones that convert light into electrical signals to the brain where they are interpreted as vision.

2.  Gift of the Creator
 Gives us the sense of sight
 70% of all sensory receptors are in the eye
 Spheroid structure, about 2/3 the size of a
ping-pong ball
 Functions: distinguishes light and dark,
shape, colour, brightness & distance of
objects.

3.  Includes : bony orbit, eyelids, eyelashes,
tears and fat glands, extra ocular
muscles, conjunctiva

4.  Most of the eye is enclosed in a bony orbit
 Structure:
o Cheekbone
o Forehead
o Temple
o Side of nose
 Function:
Provides protection to the eye

5.  A thin fold of skin that covers the eye
 Protect eye from foreign matter (dust, dirt, debris)
 Protect against bright light that might damage the
eye
 Lubricate the eye surface by distributing tears over
the cornea
Upper
eyelid
Lower eyelid

6.  Are the hairs that grow
at the edge of eyelids
 Protect the eye by
filtering out foreign
matter

7.  A thin, clear layer of skin
 Lines the inner surface of eyelids &
covers the front surface of the eye
ball except the cornea
 Secretes mucus to lubricate the eye
 Keeps bacteria and foreign
material from getting behind eye

9.  Innermost, sensitive layer of the eye
 A delicate membrane containing
photoreceptors & associated
neurons

10. Are of two main kinds:
Rods
Cones

11.  Sensitive to dim light
 Present everywhere in the retina
except the fovea
 Allow dim light vision & peripheral
vision
 125 million rods in the average
retina

12.  Sensitive to bright light
 Clustered near the centre of
retina(fovea)
 Distinguish colours & allow
sharp vision
 5 million cones in the average
retina

13.  A depression in the retina directly opposite
to lens

14.  Contains only cones & no rods
 Function: to form an extremely clear
image
 Is directed towards whatever object
you are studying most closely

15.  A point where the optic nerve enters retina
Optic disc
Optic nerve

16.  absence of cones & rods
at the optic disc
 No vision is possible here
 Referred to as blind spot

17. The bundle of over
one billion nerve
fibres that carry
visual messages
from the retina to
the brain.

19.  Arteries transmit oxygen
& nutrients
 Veins carry deoxygenated
blood from the eye

20.  Transforms light energy to
electrical signals

21. Anterior
Chamber
Posterior
Chamber

22.  A clear, watery fluid in the anterior
chamber
 Nourishes the lens & cornea and helps
refract light onto the retina

23.  A clear, gel-like fluid in the posterior
chamber
 Supports the lens & retina and keeps
the eye from collapsing
 Aids the magnifying power of the eye

24.  Light rays coming from object enter
through the cornea, progress through
pupil & fall on eye lens which converts
light rays & produces a real & inverted
image of object on retina. The image
thus formed is conveyed to brain by optic
nerve in the form of electrical signals
which are seen by the brain as a visual
image.