W3

Question 1

what is thin lense

Answer 1

A piece of optically transparent material,
bound with two polished surfaces, at least
one of which is curved.’

Question 2

what do conVEX enses do

Answer 2

• is a converging surface
• has positive power
• increases the vergence of light
  Convex and concave
  surfaces

Question 3

what do conCAVE lenses do

Answer 3

• is a diverging surface
• has negative power
• reduces the vergence of light
  Convex and concave
  surfaces

Question 4

difference between F1 and F2 equations

Answer 4

f1 is n’1-1/r while f2 is 1-n’/r

Question 5

F total equation

Answer 5

F1+F2

Question 6

PARAXIAL RAY EQUATION ORDER

Answer 6

F then L then L’ then l’

Question 7

whats the circle of least confusion

Answer 7

blur circle between the 2 focal lines which have been formed

Question 8

formula for least confusion

Answer 8

L1+L2/2

Question 9

what should you do for a Corneal Astigmatism

Answer 9

do (f90=n’n/r90) - (f180=n’-n/r180)

Question 10

what are the 2 types of astigmatism

Answer 10

Corneal astigmatism
Lenticular astigmatism

Question 11

what causes a corneal astigmatism

Answer 11

when the 2 radius’s of the cornea F180 and F90 have different values

Question 12

what causes a lenticular astigmatism

Answer 12

Toroidal surfaces, or a tilted lens