4. • The organ of
sight
• Occupies the
ant.1/3 of the
orbital cavity
• Embedded in
fat, separated
by a
membranous
sac, the fascia
bulbi.
• Eyeball
closely
resembles
the Camera
Introduction
5. • Two poles
• Two axes
• Eqator: an
imaginary line
arround the
eye ball
equidistance
from the two
poles.
• Meridian: an
imaginary
plane from
pole to pole
and cutting the
equator at the
right angle.
6. Concentric coats/tunics of eyeball
• Outer fibrous coat: Sclera and Cornea
• Middle vascular coat: Choroid, Ciliary Body
and Iris
• Inner nervous coat: Retina
7.
8. Structure piercing the sclera
• Optic nerve
• Post.ciliary
vessel and nerve
• Venae
vorticosae
• Ant ciliary artey
23. Vitreous humour/body
• The vitreous is the
transparent, colourless,
gelatinous mass that
fills the space between
the lens of the eye and
the retina lining the
back of the eye.
• It is produced by cells in
the non-pigmented
portion of the ciliary
body deriven from
embryonic mesenchyme
cells which then
degenerate after birth.
24. Vitreous Body
• Its composition is similar to the cornea, but contains
very few cells (mostly phagocytes which remove unwanted cellular
debris in the visual field, as well as the hyalocytes of the surface of the
vitreous, which reprocess the hyaluronic acid),
•
•
•
•
•
•
•
No blood vessels.
Water = 98-99% of its volume (75% in the cornea)
Salts, sugars, vitrosin (a type of collagen),
a network of collagen type II fibres
Glycosaminoglycan
Hyaluronic acid and many proteins in micro amounts.
The vitreous body has a viscosity two to four times
that of pure water, giving it a gelatinous consistency.
It also has a refractive index of 1.336
25. Lens
• The crystalline lens is a
transparent, biconvex structure in
the eye that, along with the
cornea, helps to refract light to be
focused on the retina.
• The lens, by changing shape,
functions to change the focal
distance of the eye so that it can
focus on objects at various
distances, thus allowing a sharp
real image of the object of interest
to be formed on the retina
37. Nerve supply
• Sclera:
• Cornea:ophthalmic nerve through long
ciliary nerve which form 4 plexus as they
reach the cornea (anular, proprial,
subepithelial and intraepithelial
• Choroid:
• Ciliary muscle: parasympathetic nerve
• Iris:
41. Open-Angle Glaucoma
• Primary OpenAngle
Glaucoma:
The drainage
angle is open
within the
eye, but for
unknown
reasons, does
not allow fluid
to drain.
