What is an eye chart test?

Eye graph test is a type of vision test usually performed by optometrist and uses an eye graph or a SELEBEN graph. This type of test is often used for situations in which general visions are tested to determine how well one can see. Other forms of tests are often used to indicate accurate visual acuity, usually for determining the regulation for correction lenses. The eye chart test consists of a person standing at a set distance from the eye table and reading the letters on the graph. The smallest size it can read suggests how well they see. The eye chart, also called the Snellen chart after Hermann Snelllen, which created it, usually consists of large white papers or poster with a number of black letters. These letters are arranged in rows from the top of the graph down. The upper line consists of a single, a very large letter, while the lower line is made up of many much smaller letters.

Someone who passes the eye testThe graph begins with the set distance from the graph itself, which is usually published on the wall. In the US, this distance is 20 feet (about 6.1 m), while in the UK there is a distance of 6 meters (about 19.7 feet). If the desired distance is not available, a graph that has perverted is used, and someone can look at the chart using a mirror to create the desired distance in the reflective space. The person who participates in the eye chart test then starts reading each letter, usually starts at the top of the graph with the largest letter and moves down the graph of each line reading.

The eye graph test indicates the visual sharpness of a person based on a line of line that it can read. The lowest series that a person with a standard vision can clearly read is marked as 20/20, indicato at a distance of 20 feet (about 6.1 m), it can read it. In the UK and other areas using metric measurements, this line is marked 6/6 to indicate the same idea in meters. These letters that haveThe size of this average line is twice the average lines are marked 20/40. These letters can be read during an eye chart test from someone with an average vision of up to 40 feet (about 12.2 m) far, but someone with a vision of 20/40 must be closer, at 20 feet (about 6.1 m) to read them effectively.

Similarly, someone who passed an eye chart and score 20/100 would have a very bad vision that requires a distance of no more than 20 feet (about 6.1 m) to read something that someone with an average vision could read 100 feet (almost 30.5 m) far away. The score of 20/200 or 6/60 in the UK usually suggests that someone is legally blind. However, for someone to be considered legally blind, however, when using corrective lenses, this poorly score would have to score.