Visual acuity - home test

How the Test is Performed:
There are 3 tests that can be done at home; distance vision, near vision, and macular degeneration (a condition in which the most sensitive part of the retina is destroyed).

Distance vision:
The vision chart is attached to a wall with the 20/20 line of the chart at eye level. Stand 10 feet away from the chart. The object of the test is to tell which way the letter is facing. If you wear glasses or contact lenses for distance vision, wear them for the test. Each eye is checked separately, usually the right and then the left. Keep both eyes open and cover one eye with the palm of the hand, piece of paper, or paper cup. Read the chart and tell directions beginning with the top line and moving down the lines until it is too difficult to see clearly. Record the number of the smallest line that was correct. Repeat with the other eye. Check the results against the chart.

Near vision:
This is to see how good the vision is for close work or for reading. Again, if glasses are worn for reading, wear them for the test. In this test, you hold the Near Vision test chart about 14 inches from the eyes. Do not bring the test any closer. Read the chart using both eyes. Answer this questions: Could the sentences be read without difficulty?

Amsler grid test:
This test helps detect an eye problem that causes blurred vision , distortion, and blank spots (macular degeneration). If you normally wear glasses for reading, wear them for the test. If you wear bifocals, look through the bottom reading portion. Hold the test grid directly in front, 14 inches away from your eyes, and look at the dot in the middle of the grid. Now cover one eye and continue to look at the dot. Repeat with the other eye. You should be able to see the 4 corners of the large square and be able to tell that the large square is divided into many smaller squares. Answer this question for: Did the lines disappear or look wavy instead of straight when either of the eyes were covered?

How to Prepare:
A well-lit area at least 10-feet long is needed. Measuring tape or yardstick, eye charts, tape or tack to hang the eye charts on the wall, pencil to record results, paper or plastic cup, and if possible another person to help are needed. The vision chart needs to be tacked to the wall (no windows) with Line 3 of the chart at eye level. Exactly 10 feet from the chart should be marked on the floor with a piece of tape.

Children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:



How it Feels:
There is nothing in the test to cause discomfort.

Risks:
There are no risks.

Why this Test is Performed:
The vision often changes gradually, and you adjust to the changes without realizing the change. Home vision tests are useful in early detection of eye and vision problems . Perform home vision tests every 1 or 2 years.

Normal Values:

  • Distance-vision test: All figures on line 3 are read correctly.
  • Near vision test: The ability to read the small type.
  • Amsler grid test: The answers to the questions was no for each eye.



Abnormal Results:
Abnormal results may mean there is a vision problem or eye disease and that you should have a professional eye examination.

Distance-vision test: If the 20/20 line is not correctly read, it may be a sign of nearsightedness ( myopia ), farsightedness ( hyperopia ), astigmatism , or other eye abnormality.

Near-vision test: Not being able to read the small type may be a sign of farsightedness ( presbyopia or hyperopia).

Amsler grid test: If the answer was yes for either eye, it may mean there is a problem.

Cost:
Information not available.

Special Considerations:
If there are any of the following symptoms, have a professional eye examination:

  • difficulty focusing on near objects
  • objects or faces looking blurred or foggy
  • double vision
  • impression of "skin" or "film" over the eye
  • frequently changing of glasses which are unsatisfactory
  • trouble seeing at night, trouble adjusting to darkened rooms
  • light flashes, dark spots, or ghostlike images
  • rainbow-colored rings around lights
  • vertical lines look wavy
  • eye pain
  • experiencing a blotting out of vision (curtainlike)

If children have any of the following symptoms, they should also have a professional eye examination.

  • thrusting head forward
  • eyes watering
  • crossed eyes
  • tilting head
  • excessive blinking
  • puckering the face
  • frowning, scowling, or squinting
  • sitting close to the television
  • poor grades in school




Visual acuity tests may be performed in many different ways. This is a quick way to detect vision problems and is frequently used in schools or for mass screening. Driver license bureaus often use a small device that can test the eyes both together and individually.