VISUAL SYSTEM II

Question 1

Dark Adaptation

Answer 1

when you go into a dark environment, the retina slowly becomes more sensitive to light; occurs around 20 mins

Question 2

Light Adaptation

Answer 2

Visual threshold rises; from dim to brightly lighted environment; occurs around 5 mins

Question 3

Pupillary Light Reflex

Answer 3

Protective reflex to sudden increase in light intensity

Question 4

Color Blindness is caused by

Answer 4

weakness of one cone system or from dichromatic vision in only two cone systems are present

Question 5

Visual Accommodation

Answer 5

Lens contract via circular ciliary muscle; slackens the tension on the elastic fibers

Question 6

Refraction

Answer 6

When viewing distant objects the lens becomes unaccommodated

Question 7

Emmetropia

Answer 7

Balance of the focal length and distance to cornea to retina are well matched

Question 8

How do the eyes focus on an object/near view

Answer 8

Eye must INCREASE refractive power via accommodation

Question 9

Edinger Westphal Nucleus

Answer 9

• Part of the oculomotor nucleus (CN III)
• Parasymphathetic neuron
• Terminate in Ciliary Ganglia
• recieves sensory information that is needed for pupillary constriction and accommodation

Question 10

Cataracts

Answer 10

Lens are clouded; due to aging

Question 11

Presbyopia

Answer 11

Decreased ability of lens as we age; caused by age; by age 50 the lens loses its elasticity and hardens

Question 12

How is AP generated

Answer 12

1. Light (Stimulus)
2. Cornea
3. Aqueous Humor
4. Lens
5. Vitreous Humor
6. Retina