Color distinction or the innate ability to judge the subtle differences featuring different colors is one of the finest perceptions of humans. Color blindness is either partial or impartial inability to take note of color distinctions despite the presence of light. Eye with its 'retinal cones' makes for the color perception. Faulty development of color distinguishing retinal cones accounts for color blindness. It is to be borne in mind that people with color blindness can see colors, but is unable to take note of the subtle differences. Test for color blindness also known as "Color vision test" serves to throw light on this distinguishing ability.
Different types of color blindness
- The most commonly relevant color blindness is the inability to differentiate reds & greens. Counted amongst one of the minor eye defects, color blindness of red & green is the most familiar variety.
- Vision deficiency in respect of blue & yellow comes next on line. It is largely unusual.
- Color blindness of 'unilateral dichromacy' refers to a condition wherein one of the eyes is affected by colorblindness, the other being normal in respect color sensitivity.
- People affected by 'achromatopsia' are completely color blind, they are only able to see grayish shades.
- Color blindness is not to be confused with visual acuity, for it has neither physiological nor medical relations to the latter.
Causes of color blindness
- As mentioned in the introduction, impairment in the way of retinal development, affecting its color distinguishing cones leads to color blindness.
- Genetic distribution is one of the principal causes of color distribution.
- Heredity has a part to play as well and so many a time you can inherit it from your predecessors.
- Besides the reasons of heredity and that of genetic distribution, color blindness can also result from causes of injury.
- Physical injury to eye or its associated nerve endings can bring about color blindness
- Damage to brain can be one of the causative factors.
- The subtle ability for color distinction can also take place with age.
- Diseases affecting the neural aspects of eyes including their optic nerves can result in color blindness.
Color blindness – Symptoms
- Difficulty in identify between colors
- Unable to see a few shades of color
- Unable to distinguish shades of red and green
- In rare cases people see only black, white and gray
Color blindness – Treatment
Cure has not been found out for this condition till date. Certain contact lenses or colored filters are recommended to improve the color vision deficiency. It can help in distinguishing colors but many patients find it difficult to wear.
Related Link → Click here to take a color blindness test online
Tests for colorblindness
- Vision test for color is also known as Ishihara test- having been devised by the renowned ophthalmologist from Japan- Shinobu Ishihara.
- It generally makes use of cards displaying variegated dotted patterns.
- In course of vision testing for color, you will be required to sit in a room lit up sufficiently.
- A number of cards with multihued dotted patterns will be thrown up for viewing.
- The dots of multicolor might take on either a symbol or a numerical figure.
- Separated by an approximate distance of fourteen inches, you are generally called upon to read the relevant figure or symbol put out by the respective testing cards.
- This test like any other kinds of vision testing involves individualized evaluation of both the eyes.
- Besides identifying the relevant number or symbol, you can also be required to gauge color intensity.
Relevance of color blindness test/ test for color vision
Problems related to color distinction, in addition to their scope and nature are assessed in course of test for color vision.
Results of test for color vision
- Under normal circumstances, all the colors will be distinguishable.
- If it is not so, the extent and type of color blindness can be detected.