Colour Deficiency
Around 8% of men are colour defective, often called colour blind. However, this does not mean that they can not see colour - it means that they are less able to tell the difference between certain colours and often confuse colours that the rest of us find it easy to tell apart, often reds, greens and yellows.
The standard test for colour blindness is the Ishihara test. The test consists of coloured plates of dots on which a number can be seen. A colour defective will either see a different number from a non-colour defective or will not see a number at all. However, there are some plates where the colour defective will see a number and a non-colour defective will not.
Unfortunately, being colour defective prohibits a person from certain professions such as electrician, pilot or commercial sailor.
However, it is possible to increase the number of colours a colour defective can tell apart by using a coloured filter in front of one eye. This allows the brain to compare between the two eyes and distinguish more numbers. Most colour defectives can then pass the Ishihara test.
The Chromagen tinted lens kit
It is possible to wear a specially tinted soft contact lens in one eye only to achieve this affect or alternatively, the tint can be incorporated into special mirrored spectacles either to prescription or as a clip-on. The visual improvement in colour perception and recognition generally by colour defectives can be quite spectacular
Chromagen tinted spectacles for colour deficiency
In order to try the coloured glasses or contact lenses an hour-long assessment appointment is needed with Mr Burnett Hodd or Dr Caroline Burnett Hodd. You may be asked to use a coloured contact lens or an overlay for an hour or two to see the effect and you can then decide whether to go further.
Mr Burnett Hodd has published two articles in Optometry Today about Chromagen Lenses:
Putting Chromagen to the test
The Chromagen method for colour deficiency and specific learning difficulties