When a person is not able to identify seeing certain colors, it is called color blindness.  The retina of the human eye has special pigments. These pigments react to light. There are two types of these pigments.  The cones which control color vision. The rods which help us to see at night. When there is a problem with these pigments, people become color blind.


There are various types of color blindness as follows:

  1. Protanomaly:  there is reduced sensitivity to red light and the inability to perceive color differences.
  2. Deuteranomaly:  This is a common type of color blindness.  It is associated with reduced sensitivity to green light.  
  3. Tritanomaly:  It is a very rare type and is related to reduced sensitivity to blue lighting.
  4. Complete color blindness: These people have no experience of seeing any color.  This will affect the clearness of their vision.

People belong to the first two categories are known as ‘red-green color blind’.  They have difficulty in distinguishing red, green, purple and orange. They also get confused with shades of blue.

The third category people have difficulty in identifying yellow, violet, red, blue and green.  

Color Blindness Test


The common symptoms related to color blindness are:

  1. Problems in seeing colors which are bright.
  2. Rapid eye movements
  3. Difficulty in distinguishing colors.


Glasses and lenses are very effective for people who cannot distinguish green and red.  For red and green blindness, the glasses are of great help. But for blue color blindness glasses do not provide a solution.  Recently special color lenses help people in finding a solution to their problem. These lenses add brightness to shades. So, the person who has difficulty in distinguishing these colors can find it easier. A person who is color blind will see faded colors only. With the help of lenses which make the colors bright, the person can easily distinguish the color.


The exact reason why a person becomes color blind is still being researched.  There are no full-proof treatment methods which can completely eliminate this difficulty.  Red-green blindness is inherited from parents to children.  X chromosomes carry this deficiency. Hence men have this problem more than women.  

One cannot say that this is a very big health issue.  But safety concerns are there. Imagine people not able to distinguish red and green traffic lights.  This would cause accidents.

Lenses and glasses can help these people to a great extent.  Besides visual aids are being developed to help these people.  Recently mobile phone apps have been introduced to help the color blind to distinguish colors.  

Young children may find it difficult to study and read when they are color blind.  So it becomes essential to detect color blindness at the earliest stages of youth. Some corrective action will be of great help in the daily life of color-blind people.  Research is going on to find out whether gene therapy can help. Gene therapy can help in growing the pigments properly in the retina so that vision can become normal.