|
|
|
|
Vision Screening
| |
 |
Vision Screening Test |
|
|
These vision tests can only be considered a
screening test and its validity is not guaranteed. A variety of
factors such as lighting, glare, pixel resolution and monitor
quality may have an effect on the results of this test.
|
|
Should you think that the test proved sight
problems, visit an eye doctor for a professional
assessment. |
|
|
|
Click any of the above links for your
On-line Vision Screening |
|
|
| You can test your distance vision
on-line using a Snellen Chart. The Snellen Chart is
the eye chart most doctors use and is the industry
standard. |
|
It has standard size letters and
is normally viewed at a test distance of 20 feet.
The on-line Snellen Chart will vary in size
according to the size of your screen, therefore, the
test distance will also change. You will have to use
the chart below to find proper test distance based
on the size of the letter "E" at the top of the
chart.
| Size of the
big "E" |
Feet from
screen |
| 1 1/2" |
4'3" |
| 1 5/8" |
4"7'' |
| 1 3/4" |
4'11'' |
| 1 7/8" |
5'3'' |
| 2" |
5'8'' |
| 2 1/8" |
6' |
| 2 1/4" |
6'5'' |
| 2 3/8" |
6'9'' |
| 2 1/2" |
7'1'' |
| 2 5/8" |
7'7'' |
| 2 3/4" |
7'10'' |
| 2 7/8" |
8'2'' |
| 3" |
8'6'' |
|
|
 |
|
|
Vision 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 the letters.
The "E" and "F" on the top line is equivalent to 20/400 and
20/200 respectively. A person unable to read these letters with
best eyeglass correction is considered legally blind.
The "L'' ''P'' 'E'' ''D''on the second line are equivalent to
20/100.
The third 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 fourth 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.
The bottom two lines represent 20/30, 20/20 . These are
considered to be "normal vision" with the 20/20 line being the
traditional normal vision line. |
|
|
|
|