Lecture 21 - Optics of the Eye

Question 1

anatomy of the eye:
- what is the lens and what does it do? what suspends the lens?
- what is the chamber in front of the lens called and what is it filled up with?
- what is the chamber behind the lens called and what is it filled up with? what does it do?
- what and where is the cornea and sclera? what does the cornea do to the retina? where and what is the retina composed of?
- what is the pathway of light entering our eye?

Answer 1

slide 4-5

Question 2

changing size of the pupil:
- when do the pupils constrict and why? which signals tell the eye to constrict and what muscles in the eye do the constricting?
- when do the pupils dilate and why? which signals tell the eye to dilate and what muscles in the eye do the dilating?
- the eye has a huge range of illumination: what factor do the pupils dilate wrt the constricted version? how about wrt to a sunny vs moonless night?

Answer 2

slide 7-8

Question 3

focus:
- how is focused vision achieved
- can a living thing achieve focus with just the pupil and no lense?

Answer 3

slide 9-10

Question 4

depth of field:
- when the pupil is constricted, what is the depth of field? what does this mean?
- when the pupil is dilated, what is the depth of field? what does this mean?

Answer 4

slide 11

Question 5

problem with using the pupil alone to focus light?
- what is the pro/con of pin-hole focusing?
- what is the pro/con of enlarging pin-hole focusing?

Answer 5

slide 12

Question 6

refraction:
- what is refraction? what does it lead to? when does it occur wrt refractive index?
- what two areas of the eyes are responsible for refraction? what fraction is each responsible for?
- how and why does refraction occur when our cornea is exposed in air?
- does refraction occur when our cornea is in water?

Answer 6

slide 14-15

Question 7

lens:
- what can the lens do that the cornea cannot?
- what cells make up the lens? what are the components of these cells (nucleus, proteins, blood supply)?
- how does the lens provide flexibility?

Answer 7

slide 16

• it can change shape and adjust the focus

Question 8

convex shape of the eye
- what is the shape of something that is convex? ex?
- why is the eye convex?
- what is the shape of something that is concave? what do they do? ex.?

Answer 8

slide 17

Question 9

angle of incidence
- how does refraction depend on the angle of incidence?
- what are the two things that affect the angle of incidence? if we change each factor what happens?
- for a right angle of incidence how is the bending effected?

Answer 9

slide 18

Question 10

accommodation:
- if we make our lens rounder, what happens to the light and focal point?

Answer 10

slide 20

Question 11

accommodation to alter focus:
we know that for clear vision we need the focal point to fall on the retina
- if the object is drawn closer and the lens stays flat, what happens to the focal point and focus of the person?
- how do we combat this with accomodation? why would this work?
- how does the body signal for accomodation to occur when out of focus for close and far vision? (what signals, and what muscles, what do they do, how does it effect tension, how does it effect shape, where does the focal point shift)?

Answer 11

slide 23

Question 12

accommodation
- what is the definition of accommodation
- what is near point accommodation? how and why does this change with age? what condition is this called?
- is accommodation a conscious or unconscious reflex? how can you test this?

Answer 12

slide 24-25

Question 13

hyperopia:
- what is hyperopia? what does it do to the focal point? why can this happen (2)?
- how does you solve this issue? how does this solution work?

Answer 13

slide 27-28

Question 14

myopia:
- what is myopia? what does it do to the focal point? why can this happen (2)?
- how does you solve this issue? how does this solution work?

Answer 14

slide 29-30