Can Colorblindness Be Detected Before Its Symptoms Appear?

Color blindness is a visual impairment that hinders the ability to differentiate between certain colors. The potential hazards and frustrations of color blindness often compel concerned parents to detect the disability as soon as possible. Before a child has manifested any apparent symptoms of color blindness, visual tests may be used to screen for the disorder. While color blindness remains incurable, detection in toddlers allows parents to prepare accordingly.

History

• Chemist John Dalton is credited as the first man to scientifically write on the subject of color blindness. His discoveries helped pave the way for later professors and opticians to develop tests to detect the disorder. Dr. Shinobu Ishihara, a Japanese professor at the University of Tokyo, developed one of the first widely accepted tests for color blindness. Unfortunately, the test was only capable of discerning if the patient was blind to red and green. Eventually, tests for color blindness were expanded to detect all forms of the condition. Some of the tests cater more directly toward children, enabling early detection.

Significance

• For the most part, color blindness does not inhibit a normal lifestyle. However, in situations where impeccable color detection is an absolute necessity, color blindness becomes an issue. Some professions automatically disqualify applicants who suffer from color blindness. For example, color blind pilots are restricted from night flying and are therefore not allowed airline employment. Additionally, driving an automobile can prove dangerous or difficult for a color blind person. Inability to distinguish the colors of a traffic light presents an obvious traffic hazard. However, many color blind people can differentiate between hues even if they cannot perceive them normally.

Identification

• Color blindness can be detected before the symptoms have become apparent or be confirmed following the onset of vision trouble. The Ishihara Color Test is comprised of a number of plates filled with an assortment of random dots. Select dots are shaded a different color from the rest, forming a number. To a color blind person, the shaded number will be invisible. Since a toddler is probably unfamiliar with numbers, other tests are usually administered on young children. Such tests as the Farnsworth D-15 test call for a specialized arrangement of colors while other tests require the patient to match colors. Color blindness can also be predicted before birth. Because color blindness is often a hereditary condition, the chances for genetic predisposition can be accurately predicted. Color blindness is a recessive trait carried by the X chromosome. If a person's hereditary history dictates that the color blind gene is found on all of their X chromosomes (one for a male, two for a female), it can be confirmed they will be color blind.

Types

• While there are many forms of color blindness, each type originates from either acquired or inherited causes. Color blindness can be acquired from damage incurred by the eye or brain. More typically, color blindness is inherited and takes the form of monochromacy, dichromacy, or anomalous trichromacy. Monochomacy exists when there is complete color blindness --- the world is seen in varying shades of gray. On the other hand, dichromacy and trichomacy affect the ability to perceive red-green or blue-yellow.

Prevention/Solution

• While inherited color blindness cannot be prevented, early detection helps parents and their children proactively address the situation. Teachers can be notified of a child's color blindness and take proper action. This can include using chalk that is clearly visible against a blackboard background. Providing markers and crayons that appear plainly on paper is also important.