Lecture 5 Study Guide

Question 1

the path of light and functional anatomy from cornea to retina

Answer 1

cornea –> iris/pupil –> lens –> vitreous chamber (filled with vitreous humor) –> retina (optic nerve fibers –> rods and cones –> pigment epithelium –> back of the eye)

Question 2

identify and explain the function of the cornea and lens in accommodation

Answer 2

80% of the eye’s focusing power comes from the cornea the other 20% of focal power comes from the flexible lens and it’s curvature’s adjustment to focus light on the retina

Accommodation is just the process of changing the lens shape in the eye.

Question 3

the basic function of the pupillary reflex

Answer 3

is a reflex that controls the diameter of the pupil, in response to the intensity (luminance) of light that falls on the retina of the pupil and the eye, thereby assisting in adaptation to various levels of lightness/darkness. A greater intensity of light causes the pupil to constrict (miosis/myosis) (allowing less light in), whereas a lower intensity of light causes the pupil to dilate (mydriasis, expansion) (allowing more light in). Thus, the pupillary light reflex regulates the intensity of light entering the eye.

Constriction in one eye, in
response to light, causes the other pupil to constrict, even without
direct light

Question 4

can we use our knowledge of functional anatomy in product design?

Answer 4

the size and placement of icons on
typical smart phones and tablets. They typically fall within foveal vision(roughly 2°) and are separated by white (blank) space.

For young users:
• Make visual images 
colorful, but simple.
• Text can be very small –even to exclude older 
users.

Question 5

presbyopia

Answer 5

president moping cause he’s old and can’t see

the distance of the near point will increase

• the lens gets harder and less flexible as you get older.

– The ciliary muscles controlling the lens can also weaken

Question 6

myopia

Answer 6

i’m moping cause i can’t see things far away

nearsightedness= An inability to clearly see objects at a
distance.

• Distant images are focused in front of
the retina.

Question 7

treatments for myopia

Answer 7

use a corrective

lens or to reshape (flatten) the cornea.

Question 8

hyperopia

Answer 8

i’m hyper cause i can’t see things close to me

farsightedness!!!!
• An inability to clearly see close objects.

• Distant images are focused beyond the retina.

• cause can be due to cornea or lens shape, or length of eye (too
short).

Question 9

treatment for hyperopia

Answer 9

usually a corrective

lens or surgery.