Sclera

Question 1

The sclera

Answer 1

• white of the eye is a dense layer made up of irregularly arranged bundles of collagen.

• irregularity makes the eye hard to pierce / cut through which provides great protection from foreign bodies

• white appearance is caused by the scattering of all wavelengths of light by the bundles of collagen - this can change with age

Question 2

Scleral foramina

Answer 2

Various channels in the sclera serve different purposes
• front = allows passage of blood vessels

• back = pathways for optic nerves as well as other blood vessels

Question 3

Stromal layers

Answer 3

Sclera has 3 distinct layers;
- episclera
- stroma
- lamina fusca

All 3 are made up of collagen in different arrangements and quantities

Stroma forms the bulk of the sclera and is primarily responsible for its structure and protection

Lamina fusca rich in nerve fibres and blood vessels

Question 4

Stromal layers on diagram

Answer 4

Conjunctival epithelium

Conjunctival stroma

Tenons capsule

Episclera

Episcleral vessels

Scleral stroma

Lamina fusca

Choroid