Chapter 12

Question 1

Visual Perception

Answer 1

Refraction of light
Conversion of light into nerve impulses
Transmission of impulses to the visual cortex in the occipital lobe
Perception of visual images in the primary visual cortex

Question 2

Central Visual Pathways

Answer 2

Visual fields

Binocular processing

Question 3

Retinal representation of the visual field for each eye is divided into

Answer 3

Nasal and temporal halves

Each which contains an upper and lower quadrant

Question 4

Primary Visual Cortex

Answer 4

Located in the occipital lobe

Each visual cortex receives information from both eyes

Question 5

Where is the primary visual cortex?

Answer 5

The occipital lobe

Question 6

Errors of refraction

Answer 6

Refractive errors often are the main reason a person seeks the services of an optometrist or ophthalmologist. These include: Hypermetropia
Myopia
astigmatism

Question 7

refraction

Answer 7

We see the world around us because of the way our eyes bend (refract) light. Refractive errors are optical imperfections that prevent the eye from properly focusing light, causing blurred vision. The primary refractive errors are nearsightedness, farsightedness and astigmatism.

Question 8

Visual field defects

Answer 8

Monocular blindness
Bitemporal (heteronymous) Hemianopia
Nasal Hemianopia
Homonymous Hemianopia
Homonymous Left Superior Quadrantanopsia
Homonymous Left Inferior Quadrantanopsia

Question 9

Monocular Blindness

Answer 9

Complete severing of the optic nerve

Question 10

Bitemporal Hemianopia

Answer 10

Loss of vision in the temporal visual fields
Pathology of the optic chiasm
Usually induced by a tumor of the pituitary gland
Causes blindness in the temporal visual fields for both eyes called tunnel vision

Question 11

Nasal Hemianopia

Answer 11

Loss of vision in the nasal field of one eye

Question 12

Homonymous Hemianopia

Answer 12

Loss of vision in homonymous either right or left fields for both eyes
Lesions in the right optic tract interrupts visual fibers from the retinas of both eyes resulting in a left visual field defect for both eyes

Question 13

Homonymous Left Superior Quadrantanopsia

Answer 13

Loss of vision in the superior left quadrants of the visual fields for both eyes
Temporal lobe lesion on the right side of the brain causes blindness in the left upper quadrant of the visual fields of both eyes

Question 14

Homonymous Left Inferior Quadrantanopsia

Answer 14

Vision loss in the left lower visual field quadrants for both eyes
Right sided temporoparietal lobe lesion