Colour blindness is a inherited disease?

Colour blindness is a inherited disease?

Colour blindness is a inherited disease?

Colour blindness is a genetic condition that occurs in around eight per cent of males and 0.5 per cent of females. It's passed on via a faulty chromosome and can be diagnosed via a simple colour vision test. The vast majority of patients can see many colours but have difficulty differentiating between colours, notably red and green.

Colour vision deficiency usually occurs when tiny cells inside the retina (known as cones) are not working properly. In a normal eye, the cones will respond to red, green or blue light, but if these cells are faulty a patient will find it hard to identify certain shades. In 99 per cent of cases, patients struggle to identify red and green, but blue colour blindness is also common.

Unfortunately, there's no cure for colour blindness, but it shouldn't affect day-to-day life too severely. It's usually inherited and is present from birth; however conditions such as diabetes and cataracts can lead to changes in colour vision. Therefore, if you notice anything unusual with your eyes it is important to book an eye test and see your optometrist urgently.

One of the most common tests for colour blindness is called the Ishihara test. This is often used to diagnose red-green colour blindness and is popular with optometrists. During the test you'll be asked to look at a selection plates with coloured spots. On each plate they'll be a number in a slightly different colour that can be seen by people with normal vision, but not by people with a colour defect. Colours dominate our lives.

 They have a huge bearing on the way we lead it. They are so closely related to us that everything we do from reading signs on the road to identifying a flower has a bit of colour involved in it. This association is such that they even have an effect on our mood as well for instance, gray is depressing - green is prosperous.

Colour Perception:

We recognize colours with the sensors in the retina of our eyes. These colour perception sensors are made of rods and cones.

The rods are receptive to low intensity of light and, therefore, are not sensitive to colour. They perceive images as black and white. There are about 120 million rods in the human one eye.

The cones on the other hand require a greater intensity of light. With about 7 million in number, each cone contains one of the three pigments sensitive to red, green or blue. These pigments have the capacity to absorb only a particular wavelength of colour. While short wavelength cones are able to absorb blue light, middle and long wavelength ones absorb green and red light.

When a combination of cones gets pressed into action, we see a colour that has a wavelength between the primary colours.

Visible light ranges between 380 to 780 nm on the electromagnetic spectrum. This is between the wavelength of the ultraviolet and the infrared light. A light comprising of equal proportions of all the visible wavelengths either gets absorbed or reflected. It is this reflected light that gives an object its perceived colour.

The temperature of the light source also determines an object's perceived colour. Fluorescent lamp or a camera emits white light as it corresponds to a temperature of around 6000 Kelvin and does not distort colours. Lights bulbs, on the other hand, correspond to a temperature of around 3000 Kelvin and cause objects to appear yellow.

People who have less number of particular cones suffer from colour blindness. It is a state where people are unable to perceive differences between colours. If a person is suffering from this colour perception disease, it is most likely to be genetic, which means it is in the genes. This may, however, also occur because of eye, nerve or brain damage.

Colour blindness application is designed to simulate various types of human partial colour vision. They can show the brightness information in normal colour vision and what each kind of cone sees. The applications have built-in algorithms to detect the severity of the blindness.

The science or the study of colour is referred to as the Chromatics. It signifies the basic concepts of primary colours and hues, principles regarding their saturation and brightness, web-safe colours. The study distinctively focuses upon the understanding of different colour concepts. In case of colour blindness, all these instincts and stimulations are highly affected; as a result the patient feels difficulty in recognizing them appropriately.