Vision ∙ Vue ∙ Vista ∙ Syn ∙ зрение ∙ 视力
Jens G. Hetland, Professor, MD, Ph.D, Oslo, Norway
Sponsored by Arthur and Odd Clausons Legacy for vision and eye care
for people who want to study visual acuity and visual fields interactively

Syn for alle - On Tonometry - Experimental Tonography

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A person with normal sight (emmetropia), without any type of visual correction, is able to see clearly at distance, because parallell rays are carried to focus right at the macula of the retina, when the eye is in a relaxed mode.

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Note how the lens gets thicker when reading (accommodation of the eye).

When testing visual acuity, one eye is tested at a time and subsequently both eyes together. Two eyes can usually see more sharply than one.

The results of the test is put down as numbers or fractions. The notation for full visual acuity is 1.0 or 20/20 (feet) or 6/6 (meters). One tenth visual acuity corresponds to 0.10 or 20/200 or 6/60.

The tests are for educational purposes only to illustrate hypothetical cases
This site was last updated 15 March 2010