Colour blindness is a visual disorder in which a person cannot see or perceives colours incorrectly. It is caused by a genetic or acquired defect in the colour-sensing cells (cone cells) in the eye. Colour blindness is a genetic trait usually inherited in association with the X chromosome and is more common in males. There are three main colour cones that form the basis of colour perception: red, green and blue. Colour blindness occurs when these cones do not function normally or are missing.
The most common types of colour blindness are red-green colour blindness and blue-yellow colour blindness. Red-green colour blindness refers to a condition in which it is difficult to distinguish between red and green hues, while blue-yellow colour blindness describes a condition that causes blue and yellow colours to be confused.
Symptoms of Colour Blindness
-Mixing colours
-Difficulty in perceiving certain colour tones
-Low contrast between colours
-Coloured objects appear pale or grey
Colour blindness is usually congenital, but in some cases it can occur with age or develop due to factors such as trauma or illness.
Types of Colour Blindness
Colour blindness usually has a genetic basis and causes problems in distinguishing or correctly perceiving different shades of colour. Colour blindness is usually a reduced sensitivity to the colours red, green, blue and yellow, confusion of certain shades or the inability to see colour at all. This condition is basically divided into two main types: red-green colour blindness and blue-yellow colour blindness. As a third type, complete colour blindness can also be mentioned.
Red-Green Colour Blindness
This type of colour blindness is a condition that causes difficulty in distinguishing between shades of red and green. It is caused by a genetic defect or deficiency in the red and green cones. These individuals have difficulty accurately perceiving the difference between these shades of colour. This type of colour blindness is usually genetically inherited and is more common in males.
Blue-Yellow Colour Blindness
This type of colour blindness is characterised by the mixing of blue and yellow colours. There are difficulties in distinguishing between blue and yellow colours. It is usually caused by a genetic defect or deficiency in the blue cones. It is not as common as red-green colour blindness.
Complete Colour Blindness
Complete colour blindness is the inability to perceive any colour and is a rare visual impairment. In this condition, the individual's eyes cannot recognise the differences between all shades of colour and see the world in black and white or shades of grey. Complete colour blindness usually occurs due to genetic factors and persists throughout a person's life.
Problems with colour vision are usually caused by a deficiency or defect in the cone cells in the retina. Complete colour blindness is usually caused by a complete absence of the three types of cone cells that are sensitive to the colours red, green and blue. This condition may be related to genes on the X chromosome and therefore tends to occur in males, because males have only one X and one Y chromosome.
Let's take an example of how a colourblind individual sees the world. For example, if a person has only blue colour cones, they only perceive blue and yellow colours. He/she cannot distinguish red and green. He sees the colour purple, which is a mixture of blue and red, and its shades in blue and blue tones. Because the eye lacks cones to distinguish the red colour.
How Does Colour Blindness Occur?
Genetic Couses
Colour blindness is usually caused by a genetic defect or deficiency in the cone cells in the eye, which are responsible for colour perception. The human eye has three different types of cone cells for perceiving colours, the red, green and blue cones. Colour blindness is usually caused by a genetic mutation or deficiency in one of these cone cells.
The genetic transmission of colour blindness is usually linked to the X chromosome. Therefore, colour blindness is usually more common in men because men have only one X and one Y chromosome, whereas women have two X chromosomes. If the gene for colour blindness is inherited from the mother and the father is not a genetic carrier, then the male child can develop colour blindness. Women can often be carriers of colour blindness, but do not develop colour blindness themselves.
Acquired Couses
Acquired colour blindness refers to a disorder of colour perception that usually develops due to external factors such as age-related changes, eye diseases or exposure to certain chemicals. This type of colour blindness is an acquired condition rather than a genetic factor. For example, the natural yellowing of the lens with age or the aging process of the eye can cause changes in colour perception.
Acquired colour blindness can also be caused by certain eye diseases, especially problems with the retina or optic nerve. In particular, diseases such as yellow spot degeneration can affect colour vision. Acquired colour blindness can improve colour perception by identifying and treating the underlying cause.
Colour Blindness Test
The most common test used to detect colour blindness is the "Ishihara Colour Test". This test contains a special set of coloured dots designed to determine whether individuals with colour blindness can accurately distinguish certain shades of colour.
Here are a few examples of the Ishihara Test:
This number is 12 and everyone sees this number.
You are a colour blind if you see nothing. Normal eyes see 16.
How Colour Blindness Affects Daily Life?
Colour blindness can affect individuals' daily lives in various ways. Firstly, important information such as traffic signals and coloured lights can be difficult for colourblind individuals to make sense of. For example, a person who has difficulty distinguishing between red and green lights may have difficulty responding correctly to traffic signals, which can pose a potential risk to traffic safety. However, thanks to the contrast and positioning of traffic lights, colourblind people can usually distinguish traffic signals safely.
In addition, colour blindness can also cause some limitations in work and professional areas. Especially in professions that require colour recognition or working with colour graphics, this can affect the individual's performance. In professions such as electrical engineers, pilots, graphic designers, the correct perception of colours is important and colour blindness can make it difficult to work in these professions.
Colour blindness is a visual disorder that is usually due to genetic factors. Colour blind people have difficulty distinguishing colours.