Colour blindness affects around 4.5% of the UK population, that amounts to nearly 2.7Mio people. Many of those who find it difficult to identify and distinguish between certain colours don't know that they are colour blind. Colour blindness or colour vision deficiency is more prevalent among males (about 8% of all men) than females, is usually inherited, and although sometimes it can develop later in life is rarely a sign of anything serious. Severity of colour blindness is usually divided into the following four categories: slightly, moderate, strong, and absolute and is not curable. Some people suffer from a chronic form of colour blindness called achromatopsia or monochromacy.
So why is this non-life threatening disorder important?
In some countries you need normal colour vision to get a driver's license. Colour blindness can also result in being refused a job. The most important reason is surely that missing out on the full spectrum of beauty the world has to offer simply because of this defect. It is not something you think about every day I'm sure and fortunatly, most categories of colour blindness can be corrected using lenses. Just see the reactions of some of these people who are discovering true colour for the first time.
How can you tell if you are colour blind?
The original Ishihara colour blindness test was introduced in the early last century and since then, it is by far the most well known colour vision deficiency test all around the world. Dr. Shinobu Ishihara from Japan produced three different test sets which are widely used and which are all based on the same so called pseudoisochromatic plates. It consists of 38 pseudoisochromatic plates in all, with each of them either showing a number or some lines. According to what you can or can not see, the test gives feedback of the degree of your red-green colour vision deficiency.
In order to assess your own situation, you could ask your parents if they are colour blind. Your local optition will have an Ishihara test, or you can try an online test by visiting EnChroma who manufacture glasses to correct colour blindness.