Blindness or Low Vision Flashcards
Legally Blind
Visual Acuity: 20/200 or less WITH correction.
Field of vision: less than 20 degrees.
Low Vision
Visual acuity - between 20/70 and 20/200 WITH correction.
Blind (Educational)
Must learn to read BRAILLE.
Low Vision (Educational)
Can read print with magnification.
Prevalence
- 2% of children in Canada, aged 0-14.
0. 04% of children in the U.S., aged 6-21 years.
What are some limitations of the Snellen chart?
1) Does not measure visual acuity for near objects.
2) Visual acuity may not correspond to visual efficiency (ability to control eye).
3) Acuity may not correspond to use of vision in natural settings.
Functional Vision Assessment
Observing the student interacting in different environments (e.g., classroom, outdoors, grocery stores), under different lighting conditions to see how well the student can identify objects and perform various tasks
Myopia
Nearsightedness.
Hyperopia
Farsightedness.
Astigmatism
Blurred vision.
Cortical Visual Impairment
This is the leading cause of blindness in children, and is caused by damage to parts of the brain.
Optic Nerve Hypoplasia
This is caused by an underdevelopment of the optic nerve and is usually accompanied by other disorders.
Retinopathy of Prematurity
This is an abnormal growth of blood vessels in the eye. which then causes the retina to detach.
Strabismus
Condition in which one or both eyes are directed inward or outward.
Nystagmus
Condition in which rapid involuntary movements of the eye occur, usually resulting in dizziness and nausea.
