I SEE

Eye Charts

If you want to improve your vision with natural vision improvement techniques, such as the Bates Method, you need an eye chart. With an eye chart, you can perform various eye exercises, and, of course, an eye chart provides an objective way for you to see your progress as you improve your visual fitness. As you experiment with various vision improvement techniques, the eye chart can help you decide which exercises work and which ones don't work for you.

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Check out the eyechart download section for free eye charts, ready to print out (or use on screen) and use in measuring and training various aspects of vision; or, follow the instructions on how to make your own eye chart!

Using a Snellen eye chart

The chart is usually read while standing at a distance of 20 feet. Acuity is represented as a fraction, with the distance at which you are standing being the numerator (top part of fraction), and the normal maximum legible viewing distance ("Distance" on the chart above) as the denominator (bottom of fraction). So if, at 20 feet, you can read the letters on the row marked "40", this means you have visual acuity of 20/40 or better: 1/2 normal. From 10 feet, if the smallest letters you could read were on the "40" line, this would give you an acuity of 10/40: 1/4 normal. If you are nearsighted, your vision will become more normal the closer you stand to the chart.

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Free eye charts to download!

Make your own eye chart!

For those enterprising souls out there who would like to laserprint or draw by hand their own eye chart, or if you would like to verify that your printout is of the correct proportions, here are the specs:
Distance (feet)  70   60    50    40    30    20    15    10    7    4
letter ht (mm)   31   27    22    18    13     9     7     4    3    2
letter ht (pt)   88   76    63    50    38    25    19    13    9    5
font size (pt)  152  130   108    87    65    43    33    21   15    9
With the University at Buffalo's Interactive Visual Acuity Chart, you can display the letters or symbols for a specified Snellen line on your computer monitor at exactly the right size (note: you must follow the instructions for calibration).

Interpreting the table

"Distance" in the above table refers to the furthest distance from the chart at which a normal eye is able to read the letter. On a Snellen eye chart, rows of letters of a given size have the corresponding distance number next to them. Thus the row of 18mm letters is marked "40". The font must be Courier (or Courier Bold) in order for the "font size" in points to correspond to the indicated letter height. Courier Bold is the PostScript font that most closely approximates the official Snellen letters.
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Revised 15 Jun 2009