Anatomy

Question 1

What are the three layers that form the wall of the eyeball?

Answer 1

1. Protective coat = sclera (+ cornea) - tough outer layer
2. Vascular coat = uveal tract - highly vascular (choroid posteriorly, ciliary body and then iris anteriorly)
3. Retinal layer = pigmented layer then neural layer

Question 2

How does the retinal layer of retina absorb light?

Answer 2

Neural layer contains rods and cones aka light receptors
They are transducers which convert electromagnetic energy (light) into electrochemical energy ie action potentials
This is then absorbed into pigmented layer

Question 3

Where does the retinal layer extend to?

Answer 3

Neural layer extends from optic disc to roughly 2/3 anteriorly (before ciliary bodies)
NB retina is only sensitive to light in areas where neural layer is present
Pigmented layer extends further anteriorly to iris

Question 4

How is the lens held in place?

Answer 4

By suspensory ligaments

Attached to ciliary bodies