Visual Development (M1) Flashcards Preview

II. Neurophysiology and Perception > Visual Development (M1) > Flashcards

Flashcards in Visual Development (M1) Deck (17)
Loading flashcards...
1
Q

What are differences in the photoreceptors of newborn infants in the fovea?

A
  1. cones are flat
  2. outer segments are short
  3. no fibers of Henle
  4. Ganglion cells bodies in one layer
  5. No foveal pit
2
Q

What are the Muller cell glia located between bipolar and amacrine cell bodies in the infant fovea called?

A

Transient layer of Chievitz

3
Q

What is different about the inner nuclear layer at the fovea in infants compared to adults?

A

there is no inner nuclear layer at the fovea for adults but there is for infants

4
Q

What percentage of ganglion cells that a person is born with eventually die?

A

50%

5
Q

Where is the optical aperture of adult cones? 1. Newborn cones? 2

A
  1. inner segment’

2. not sure but not in inner segment

6
Q

What is the idea that light entering a cone directly is more likely to be absorbed and looks brighter then a light entering a cone at an angle? 1. What is this due to?

A
  1. Stiles-Crawford Effect

2. waveguiding by the cone inner segment

7
Q

Why does much of the light that enter the cones of a newborn not reach the cone outer segments?

A

little or no waveguiding so no Stiles-Crawford effect

8
Q

What is the type of Albanism where the lack of pigment is not absolute and visual signs and symptoms are less severe? 1. What is the more severe one? 2

A
  1. Ty+

2. Ty-

9
Q

What is the gold standard for infant acuity?

A

Teller acuity cards

10
Q

Are the Teller Acuity cards a forced-choice preferential looking method or a yes/no method?

A

yes/no method

11
Q

What is the rule for a normal acuity of a baby during development?

A

acuity in cycles per degree is about as good as their age in months

12
Q

What is the pattern of a baby’s increment threshold?

A

same pattern as adult but shifted up x50 for intensity for the baby

13
Q

How does a baby’s and adults threshold evaluating power of the background compare? 1. What does this info indicate? 2

A
  1. same

2. baby rods are just about as sensitive to change as ours (obey Weber’s law)

14
Q

By what age can normal color vision be demonstrated?

A

3 months

15
Q

What type of color vision come in later than the other types?

A

S-cone (tritan) comes in later than L and M cone discrimination

16
Q

When does the visual acuity plateau to be the same as an adult?

A

3 years old

17
Q

When is VEP resolution acuity at adult values?

A

1 year old