Test Your Eye with Eye Charts

Snellen Chart, Landolt C, Lea Test

I wonder if I see things as clear as others do, or I do more, or I do less....!?

Eye charts are a great help to the objectivity of my assessment of myvisual acuity.

They are of various different kinds, each one designed and made with a different kind of purpose in mind.

Various kinds of symbols have been designed for these charts, facilitating identification by illiterates and children alike. Some of them are the capital block letter "E" turned in different orientations, the "broken ring" chart with different segments missing called Landolt C, eye charts comprisingsimple pictures called Lea Test, et cetera et cetera.

These charts comprise different rows of test symbols in different sizes.

Snellen Eye Chart

You start with the row comprising the largest test symbols and go on identifying them in the next and next rows till you are comfortably able to do so.

Once you face a difficulty in identifying in a particular row, you stop there and your vision is calculated according to its power as being able to identify upto the previous row only.

The calculation part is very easy. The rows are supposed to be identifiedfrom a distance of 200 feet (for the largest one) to 4 feet (for the smallest).

If you can identify the symbols in the 4 feet row from a distance of 4feet, your vision is said to be 4/4 or 20/20 or 6/6.

If you can identify the symbols in the 7 feet row from a distance of 7feet, your vision is said to be 7/7 or 20/20 or 6/6.

If you can identify the symbols in the 10 feet row from a distance of 10feet, your vision is said to be 10/10 or 20/20 or 6/6.

But if you can only identify the 15 feet row (supposed to be identified from 15 feet) from a distance of 10 feet, your vision is said to be 10/15or 20/30 or 6/9.

And If you can identify the symbols in the 20 feet row from a distance of20 feet, your vision is said to be 20/20 or 6/6.

Snellen Eye Chart

If you can only identify the 30 feet row (supposed to be identified from 30feet) from a distance of 10 feet, your vision is said to be 10/30 or 20/60or 6/18.

If you can only identify the 40 feet row (supposed to be identified from 40feet) from a distance of 10 feet, your vision is said to be 10/40 or 20/80or 6/24.

If you can only identify the 50 feet row (supposed to be identified from 50feet) from a distance of 10 feet, your vision is said to be 10/50 or20/100 or 6/30.

If you can only identify the 60 feet row (supposed to be identified from 60feet) from a distance of 10 feet, your vision is said to be 10/60 or20/120 or 6/36.

If you can only identify the 70 feet row (supposed to be identified from 70feet) from a distance of 10 feet, your vision is said to be 10/70 or20/140 or 6/42.

If you can only identify the 100 feet row (supposed to be identified from100 feet) from a distance of 10 feet, your vision is said to be 10/100 or20/200 or 6/60.

If you can only identify the 200 feet row (supposed to be identified from200 feet) from a distance of 10 feet, your vision is said to be 10/200 or20/400 or 6/120 that comes under the purview of legal blindness.

Tibetan monks also created Tibetan eye charts. These eye charts are said to train the muscles and nerves of the optical system, correcting visual problems along with measuring visual acuity.

Vision therapy does the same thing, i.e., correct vision, but only with the benefit that it is instantaneously done through third eye opening.