Vision Tests
Color Vision Tests
Why It Is Done
Visual acuity tests may be done:
- As part of a routine eye examination to screen for vision problems. How often you should have routine eye examinations changes as you age:
- Once between the ages of 3 and 5
- Before a child begins first grade, then every 2 years
- Once between the ages of 20 and 29
- Twice between the ages of 30 and 39
- Every 2 to 4 years between the ages of 40 and 65
- Every 1 to 2 years after age 65
- To monitor an eye problem, such as diabetic retinopathy.
- To determine if you need glasses or contact lenses to improve your vision.
- After an injury to the eye.
- When you obtain or renew your driver's license or for some types of employment.
Refraction is done:
- To determine the correct prescription for eyeglasses or contact lenses.
Visual field tests may be done:
- To check for vision loss in any area of your visual field.
- To screen for eye diseases, such as macular degeneration and glaucoma, which cause gaps in the visual field.
- To look for damage to the nerves of the eye following a stroke, head injury, or other condition that causes reduced blood flow to the brain.
Colour vision tests may be done:
- As part of a routine eye examination.
- To screen for or diagnose colour blindness.
- To screen applicants for jobs in which colour perception is important, such as truck driving, electronics, or the military.
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| Author: | Alison Allen | Last Updated: August 16, 2007 |
| Medical Review: | Patrice Burgess, MD - Family Medicine Ian MacDonald, MDCM, FRCSC - Ophthalmology Andrew Swan, MD, CCFP, FCFP - Family Medicine | |
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| Topic Contents | |
| Test Overview | |
 | Why It Is Done |
| How To Prepare | |
| How It Is Done | |
| How It Feels | |
| Risks | |
| Results | |
| What Affects the Test | |
| What To Think About | |
| References | |
| Credits | |