Vision Tests

Various vision tests are performed to check the different functions of the eye. These tests measure the ability of a person to see details at near and far distances, check for gaps or defects in the field of vision and evaluate one's ability to see different colors.

There are four types of vision tests, these are visual acuity tests, refraction, visual field tests and color vision tests.

Visual acuity tests are the most common tests used to evaluate eyesight and are done as part of a routine eye exam to screen vision problems. In visual acuity tests, the eye's ability to see details at near and far distances are measured by reading letters or looking at symbols of different sizes on an eye chart. The normal vision is 20/20, which means that a person can read line marked 20 from 20 feet distance.

Refraction is a test that measures the eyes' need for corrective lenses and is usually done after a visual acuity test. Although this test is a routine part of an eye examination for people who are already wearing glasses or contact lenses, it will also be done if other visual acuity tests show that the eyesight is below normal and can be corrected by glasses.

Visual field tests are used to check for gaps in peripheral vision while color vision tests are performed to check a person's ability to distinguish colors. Color vision tests are used to screen for color blindness. These tests are normally used to screen applicants for jobs in fields where color perception is essential.

Having your vision checked is important. Actually, the first eye check-up must be done when a person reaches the age of 5 and if no problem is detected the check-up should continue every 5 years till the age of 40. People aged 40 years and above must have an eye check-up each year or every two years in order to detect eye blinding diseases.