Visual Fields

Question 1

How many degrees is the nasal visual field?

Answer 1

60 degrees

Question 2

How many degrees is the superior visual field?

Answer 2

60 degrees

Question 3

How many degrees is the inferior visual field?

Answer 3

75 degrees

Question 4

How many degrees is the temporal visual field?

Answer 4

100 degrees

Question 5

How many degrees of binocular overlap should there be?

Answer 5

120 degrees

Question 6

Where to retinal nerve fibers of the retina converge?

Answer 6

At the optic nerve

Question 7

Nasal fibers of the retinal nerve fiber layers represent which part of the visual field?

Answer 7

Temporal visual field

Question 8

Inferior fibers of the retinal nerve fibers represent which part of the visual field?

Answer 8

Superior visual field

Question 9

Which fibers are considered “pre-chiasmal”?

Answer 9

Nasal and superior fibers - fibers traveling from the eye to the chiasm

Question 10

What percent of the post-chiasmal fibers travel to the lateral geniculate nucleus?

Answer 10

80%

Question 11

Where do the other 20% of the post-chismal fibers go?

Answer 11

Pretectal nucleus in the midbrain - to control the pupils

Question 12

If there is lesion in the optic chiasm, what do the visual fields look like?

Answer 12

Bitemporal hemianopia - R and L temporal fields impacted

Question 13

If there is a post-chiasmal lesion, what do the visual fields look like?

Answer 13

Same side of both eyes affected

Question 14

How many layers are there in the lateral geniculate nucleus?

Answer 14

6

Question 15

What are the first 2 layers of the LGN? What do they do?

Answer 15

Magno cellular - for moving stimuli

Question 16

What are layers 3-6 of the LGN? What are they for?

Answer 16

Parvocellular - for color and acuity

Question 17

The inferior fibers of the LGN represent which part of the visual field?

Answer 17

The superior portion

Question 18

The inferior fibers of the LGN travel via ___ to the temporal lobe.

Answer 18

Meyer’s loop

Question 19

What does PI-TS stand for?

Answer 19

Parietal lobe - Inferior fibers

Temporal lobe - Superior fibers

Question 20

What does the central visual field involve?

Answer 20

Fixation

Question 21

What does the centrocecal visual field involve?

Answer 21

Fixation to blind spot

Question 22

Where is the paracentral visual field?

Answer 22

Adjacent to fixation (central)

Question 23

Where is the pericentral visual field?

Answer 23

Surrounding fixation (central)

Question 24

What is a scotoma?

Answer 24

Absolute or relative area of poor visual function surrounded by a normal visual field

Question 25

What does it mean to have a homonymous visual field defect?

Answer 25

Same side visual field loss (Ex. Right field of left eye, right field of right eye)

Question 26

What does it mean to have a heteronymous visual field defect?

Answer 26

Opposite field loss (Ex. Left field in left eye, right field in right eye - bitemporal hemianopsia)

Question 27

On whom should the amsler grid test be performed?

Answer 27

Patients over 50 Diabetics People with a history of macular degeneration People on toxic medicines People with reduced acuities

Question 28

At 30 cm, how many degrees does each block of the Amsler grid represent?

Answer 28

1 degree