|The blue "standardization
bar" must be measured in centimeters on your computer screen or
printout. You should then stand in a position back from your computer
screen so that your eye is this same number of feet from the screen.
i.e. if the blue bar measures 9 1/2 centimeters in length, you should
stand back so that your eye is 9 1/2 feet from the screen.
testing should be performed on each eye separately, wearing distance
eyeglasses if required. There are six lines on the screen, you should
note the last line number in which you can read most (50-75%) of
letter of the top line is equivalent to 20/200. A person unable
to read this letter with best eyeglass correction is considered
|The "T" and
the "B" on the top line are equivalent to 20/100. The second line
is 20/50. Best corrected acuity in the range between 20/50 and 20/100
is considered disabling in occupations which require work with numbers
or extensive reading.
|The third line
is equivalent to 20/40, it is the "driver's test" line. You must
be able to read most of the letters on this line in order to obtain
an unrestricted drivers license in most states including Massachusetts.
three lines represent 20/30, 20/20 and 20/10. These are considered
to be "normal vision" with the 20/20 line being the traditional
normal vision line. It is generally felt that the maximum visual
acuity of the eye is around 20/15 or 20/16. This means that if you
are able to read the bottom line, you are probably a good guesser.
This vision test can only be considered a screening test. A variety of
factors such as lighting, glare, monitor quality may have an effect on
the results of this test.