Your doctor will also tell you if you have reduced near vision.
The doctor tests your eyes
with different lenses until the lens that corrects your vision the best
(sometimes better than 20/20 or 6/6) is found. The result of a refraction test
determines your prescription eyeglass or contact lens strength.
Visual field test
Normally, a person's visual
field forms a rough circle with a natural blind spot. If your vision is normal,
you should be able to see objects clearly throughout the entire visual field
except for the area with the natural blind spot. When you are using both eyes
to see, the blind spots do not interfere with your vision.
have vision loss in certain areas of the visual field if you are not able to
- Test objects during tangent screen
- Movements or light flashes during perimetry
Abnormal results during Amsler grid testing
- Not being able to see the black dot at the
center of the grid.
- Not being able to see all four edges of the
- Having blank spots or dark spots on the grid (other than the
black dot at the center).
- Seeing lines that look wavy or
Gaps in different parts of the visual field may have many
causes, including eye diseases (such as glaucoma and macular degeneration) or
nervous system problems (such as stroke). If results on any of the visual field
tests are abnormal, you will need further tests to determine the cause.
Color vision test
People who have normal color
vision are able to distinguish the colored numbers, symbols, or paths from the
background of colored dots.
If you are not able to distinguish
some or all of the colored patterns from the background, you may have a color
vision problem. You may be able to pick out some patterns of colors but not
others. Or you may be able to pick out patterns that are different from a
person with normal vision, depending on what type of color vision problem you
Many conditions can change your vision test results.
Your doctor will discuss any significant abnormal results with you
in relation to your symptoms and past health.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Your ability to understand or follow
instructions. Some vision tests cannot be done on babies, small children, or
people who cannot understand or follow the instructions.
ability to stay alert and respond to questions.
- Failure to wear
prescribed eyeglasses or contact lenses.
- Poor lighting.