If you feel that you have visual impairment, this table may help you. The only thing you need to do is to determine how far you want to go from the monitor according to the size of your monitor and the screen resolution.
Try to read by closing one eye at the top to the lowest order, if you have difficulty reading it, you should immediately apply to an ophthalmologist. You may have a myopia or hyperopia.
Your viewing distance according to the screen resolution,
Screen size Resolution 640×480 800×600
14 inches 5.5 m 4.0 m
15 inches 6.0 m 4.5 m
17 inches 7.0 m 5.5 m
Color Blindness Test
COLOR can detect and distinguish the colors of an eye by the iris layer in the human eye. Due to a problem in the iris layer, it is possible to see some colors or all colors in gray.
If you cannot distinguish colors that express different numbers from the surrounding colors, you may be color blind.
Amsler Grid Test
Although it is not a routine eye examination, it is a diagram that will allow you to determine the early signs of age-related yellow spot disease by applying it yourself at home. Everyone over the age of 40 is of great benefit in implementing this test.
• Attach the diagram to the wall in a well-lit room, at the proper reading distance and at the center point, at full eye level.
• Wear the glasses that you normally use to read.
• Close one eye with your hand and focus on the center of the open eye.
• Make sure you see all four corners of the large square in the diagram.
• Repeat the application separately for both eyes.
You can consult an ophthalmologist if you cannot see every corner or see fluctuations, ruptures, blur in the lines.