Please read the following istructions before taking color blindness test:
Who should be tested for color vision deficiencies?
All children, but especially boys, should have their color vision testedat their first test and considering the patient's family history of color vision deficiency, especially on the mother's side (mother's father or brother). Because the color blindness test contains only numerals, it may not be useful in diagnosing very young children, who have not yet learned to use numerals. With younger children, distinguishing a red bottle cap from caps of a different color may be the test.
When a patient presents with symptoms that suggest impaired colordiscrimination.
For occupational purposes.
When an acquired defect is suspected as a result of an ocular orsystemic disease, or a side effect of medication or injury.
How to use the test?
When it is convenient only to use electric light, it should be adjusted as faras possible to resemble the effect of naturaldaylight.
Put the screen at 75 cm sothat the plate is at right angles to the line of vision .
The patient should be instructed to read number(s)seen on each pageand should be informed that on each page,either none, one or two digits may be seen.
The patient should not wear tintedspectacles or contact lenses during the test.
If the child normally wears glasses,wear them during the test.