What chart is used for visual acuity?

What chart is used for visual acuity?

Snellen chart
The visual acuity test is used to determine the smallest letters you can read on a standardized chart (Snellen chart) or a card held 20 feet (6 meters) away. Special charts are used when testing at distances shorter than 20 feet (6 meters).

What are visual acuity measurements?

Visual acuity (VA) is a measure of the ability of the eye to distinguish shapes and the details of objects at a given distance.

What is the Snellen E chart used for?

The projected or wall-mounted Snellen eye chart, usually topped by the big letter “E”, is a common visual acuity test used to measure your sharpness of vision at multiple distances.

How do you measure visual acuity in Snellen chart?

Normal Results Visual acuity is expressed as a fraction. The top number refers to the distance you stand from the chart. This is often 20 feet (6 meters). The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.

How do you check a Snellen chart?


  1. Ensure good natural light or illumination on the chart.
  2. Explain the procedure to the patient.
  3. Wash and dry the occluder and pinhole.
  4. Test each eye separately – the ‘bad’ eye first.
  5. Position the patient, sitting or standing, at a distance of 6 metres from the chart.

How do you use a vision chart?

How to Use the Eye Chart

  1. Print the free eye chart on regular 8 1/2 x 11-inch paper.
  2. Tack or tape the chart to a windowless wall in a well-lit room at eye level.
  3. Measure ten feet from the wall.
  4. Cover one eye (if you wear glasses for distance vision, keep them on)

How does Snellen chart detect vision?

A person taking the test covers one eye from 6 metres or 20 feet away, and reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that specific eye.

What is a distance visual acuity test?

During an eye test, your optician will use a chart of letters (“eye chart”) to measure how well you see objects at least 6 meters (20 feet) away. This is called distance visual acuity testing.

How to use an eye chart for testing vision?

Snellen Eye Chart for Testing Vision 1 Visual Acuity Testing. When testing for visual acuity, the patient covers one eye and reads aloud the letters on the chart, beginning at the top and moving toward the bottom. 2 Results. The results of your acuity exam (chart reading) will determine the quality of your eyesight. 3 Versions.

How is visual acuity measured on a LogMAR chart?

With a LogMAR chart, to measure metric visual acuity, the clinician will measure the testing distance in meters. The clinician will next note the letter size read in M units. The visual acuity is then recorded as Test distance (m)/Letter size read (M units).

What is visual acuity and how is it corrected?

Most of the time, lower visual acuity can be corrected by eyeglasses, contact lenses, or refractive surgeries. What is a Visual Acuity Test? Visual acuity is measured by charts, optical instruments, or computerized tests. Eye charts are the most common method of visual acuity testing.

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