Color blindness

Overview

Color blindness, also known as color vision deficiency, is a disorder characterized by inability to distinguish between specific colors. This occurs when cones, a type of nerve cell in the retina of the eye, do not function properly. Color blindness is frequently hereditary.

Most colorblind people see a variety of colors, although they see some colors differently than others. They may have difficulty distinguishing between different colors or tints. The real color blindness, where everything appears in black and white, is rare. Men are more likely than women to be born colorblind.

The majority of individuals who experience color blindness have difficulty telling apart specific shades of red and green. In rarer cases, people with color blindness face challenges in distinguishing between various shades of blue and yellow.

Although this condition is commonly passed down from biological parents, color deficiency can develop later in life due to medical disorders or other factors.

Symptoms

Many people who are colorblind are unaware of their condition since they have always viewed colors in the same way. Ideally, before starting school, children should receive a full eye exam that includes colorblind testing. Mild, moderate, and severe defects are all possible. 

Some people discover that them or their child has the condition when it creates confusion, such as when they have difficulty distinguishing between the colors of a traffic light or deciphering color–coded learning materials. These things may be difficult for children who view colors differently. 

Colorblind people may be unable to distinguish between: 

• Various shades of red and green
• Various shades of blue and yellow
• Any color combination

Regular eye check ups are important for overall eye health. Cases of color deficiency are often detected during comprehensive eye exams. If one feels they have difficulty distinguishing colors or if the color vision changes, consult a healthcare provider for proper diagnosis. If the reason for the color deficiency is illness or eye disease, treatment may help enhance color vision. 

Causes

The ability of the eyes to react to different wavelengths of light is the first step in seeing colors across the light spectrum. Cones are retinal nerve cells that sense colors in the visible spectrum of light. This spectrum encompasses all wavelengths visible to humans. These vary in length from 380 nanometers (nm) to 700 nanometers (nm). 

Cones are sensitive to light with short (blue), medium (green), or long (red) wavelengths. Chemicals in the cones cause a reaction, sending wavelength information to the brain via the optic nerve. Most people have all three types of cones, and they all perform properly. If one has color blindness, at least one sort of cone is not working properly. Cone problems impair the capacity to see colors in the usual sense. 

Color blindness may be caused by:

• Age: The capacity to recognize colors slowly deteriorates with age. 
• Genetic disorder: Inherited color blindness is caused by a mutation in the genes. The most prevalent variety, red–green color blindness, is inherited through an X–linked recessive pattern. Conditions inherited in this manner typically affect males and are rare among females. 

One can be born with a mild, moderate, or severe form of the condition. The most frequently occurring type of color deficiency involves challenges with distinguishing red and green hues, whereas difficulties with blue and yellow hues are less frequent. Completely lacking color vision is an unusual occurrence. These hereditary color deficiencies typically impact both eyes and remain consistent in their severity throughout one’s lifetime.

• Diseases: Certain medical conditions can affect the brain or nervous system. The impact on one eye might differ from the other, and addressing the condition could lead to an improvement in the color deficiency. Common conditions linked to color blindness include sickle cell anemia, diabetes, macular degeneration, Alzheimer’s disease, multiple sclerosis, glaucoma, Parkinson’s disease, chronic alcoholism, and leukemia. 
• Specific medications: Drugs that are used to treat autoimmune illnesses, cardiac diseases, high blood pressure, erectile dysfunction, infections, neurological disorders, and psychiatric problems, can potentially impair color perception.
• Chemicals: Carbon disulfide, organic solvents, solvent mixtures, heavy metals, and fertilizers are chemicals that may harm the nervous system and induce color vision loss.