Lens MT

Question 1

lens contributes what refractive function to the eye?

Answer 1

+20 D

Question 2

lens contributes how much accommodation?

Answer 2

12-15 D in young individuals

Question 3

protective function of the lens is:

Answer 3

chromophores absorb UV and removal of UV radiation that gets through

Question 4

thickness of lens capsule surrounding the entire lens is:

Answer 4

about 13 microns, but varies

Question 5

lens capsule composition anteriorly is

Answer 5

basement membrane of the epithelial cells

Question 6

lens capsule composition posteriorly is

Answer 6

cortical fibers

Question 7

thinnest area of the lens capsule is

Answer 7

posterior pole of capsule

Question 8

thickest area of the lens capsule is

Answer 8

anterior in mid-periphery of the capsule

Question 9

lens capsule composition and %

Answer 9

• type IV collagen
• glycosaminoglycans (10%)
• heparin sulfate (4%)

Question 10

where is the epithelium of the lens located?

Answer 10

anterior surface of the lens

Question 11

the apex of the lens epithelial cells faces what direction?

Answer 11

towards the center of the lens

Question 12

most epithelial cells of the lens are connected via:

Answer 12

gap junctions and tight junctions

Question 13

what is formed from the differentiation of epithelial cells and occurs throughout life?

Answer 13

lens fibers