4. •Six tiny muscles that surround
the eye and control its movements.
•4 rectus muscles are to control
the eye's movements from left to
right and up and down.
•2 oblique muscles move the eye
and rotate the eyes inward and
outward.
•All six muscles work in unison to
move the eye.
ExtraOcular Muscles
5. CONJUNCTIVA
• The conjunctiva is the clear, thin membrane that covers
part of the front surface of the eye and the inner surface
of the eyelids.
• It is nourished by tiny blood vessels that are nearly
invisible to the naked eye.
• It also secretes oils and mucous that moisten and lubricate
the eye.
6. SCLERA
•
• The sclera is the opaque, fibrous, tough, protective outer layer
of the eye (“white of the eye”).
• The sclera provides protection and form
7. CORNEA
• The cornea is the clear front surface of the eye. It lies
directly in front of the iris and pupil, and allows light to
enter the eye.
• The cornea have 5 layers (from outside to inside):
Epithelium, Bowman's membrane, Stroma,
Descemet's membrane and the Endothelium
8. IRIS
• The iris is thin, circular structure made of connective tissue and
muscle that surrounds the pupil.
• The color of our eyes is determined by pigment called melanin.
• The iris is embedded with tiny muscles that dilate (widen) and
constrict (narrow) the pupil size.
• The iris is flat and divides the front of the eye (anterior chamber)
from the back of the eye (posterior chamber).
9. PUPIL
• The pupil is the opening in the center of the iris.
• The size of the pupil determines the amount of light
that enters the eye.
PUPIL
10. Posterior & Anterior Chamber
Posterior & Anterior Segment
• Anterior chamber Space between cornea and iris
• Posterior chamber Space between iris and lens
• Anterior Segment – From Cornea to the Posterior Capsular Bag
• Posterior Segment – From Posterior Capsular Bag upto Retina
11. LENS
• The lens is a transparent structure in the eye that,
along with the cornea, helps to refract light to be
focused on the retina.
• The lens is encased in a capsular-like bag and
suspended by tiny zonules.
12. VITREOUS
• The vitreous is a thick, transparent gel like
substance that fills the center of the eye. It is
composed mainly of water and comprises
about 2/3 of the eye's volume, giving it form
and shape.
13. RETINA
• Retina: is the nerve layer that lines the back of the eye, senses light, and creates
impulses that travel through the optic nerve to the brain.
• There is a small area, called the Macula and allows us to see fine details clearly.
• There are two types of photoreceptors in the retina: rods and cones.
The retina contains approximately 6 million cones. Cones function best in bright
light and allow us to appreciate color.
There are approximately 125 million rods. They are spread throughout the
peripheral retina and function best in dim lighting. The rods are responsible for
peripheral and night vision.
14. OPTIC NERVE
The optic nerve may be found in your eye, but it is part of the
central nervous system. The optic nerve takes visual
information gathered from your eye and transmits it using a
series of electrical impulses to the parts of your brain that act
as vision centers, allowing you to make sense of what you are
seeing.