PDF - Visual Flashcards
Which are functions of the macula?
- Color vision
2. Acuity
What does 20 / 100 vision mean?
Person can read at 20 feet, what normal person can at 100
What does improved vision on looking through pinhole mean?
Problem is ocular
- If not improved it is nervous, or macular
What is scotoma?
Pathologic blind spot in the visual field
- Due to lesions in retina or optic nerve
What pathology does tunnel vision suggest?
Psychiatric
What is hemianopsia?
Visual loss in half of a visual field
What is homonymous hemianopsia?
Visual loss in nasal half one eye and temporal half other eye
Presentation optic neuritis?
- Sudden blindness (could be partial) in one eye
- Achy / tender with movement
- Poor constriction to light in sick eye
- Normal with light in other
- Swollen disk
What is cortical blindness? Cause?
Severe visual loss from bilateral occipital lobe lesions
Stroke in:
1. Distal basilar artery
2. Or PCA emboli
What is conductive deafness?
Problem before the hair cells
When is low tone hearing loss seen?
Conductive deafness
When is high tone deafness seen?
Neurological deafness
When is unilateral neurological deafness seen?
CNVIII lesion
How does weber test work?
- Fork to forehead
- If nerve deafness in one ear, tuning fork better in other
- If conductive, heard better in deaf ear
How does the Rinne test work?
- Hold fork at mastoid
- Hold fork outside ear - should still be heard after cant in bone since air is better than bone
- If nerve deafness, air still better than bone. If conductive, cant hear in air
