Color blindness is a disorder that affects the way an individual perceives color. The retina detects colors through cone cells. There are three types of cones in the human eye, each containing a specific photo-pigment that is most sensitive to particular wavelengths of light, i.e. red, blue or green. Individuals affected with deteranopia have no working green cone cells. Green colors may appear beige. The less severe condition of deuteranomaly is caused by abnormal green cone photo-pigment. Yellow and green appear redder in this disorder.
Deuteranopia affects males much more often than females. Studies show the rate of incidence to be about one in ten males and only one in two hundred females. The disorder is also more prevalent among the northern European population compared to other ethnicities. Deuteranopia has been found to be more common than protanopia, the disorder affecting red cone cells. While deuteranopia does not affect visual acuity, the inability to perceive colors properly may affect people’s day to day lives. Children are particularly inconvenienced by the disorder as most educational aids in classrooms are color-coded. Hence proper diagnosis must be a priority. Multiple tests have been designed to diagnose the condition. The Ishihara plate test, for example, uses colored circles which contain a collection of dots in different colors and sizes. The dots form a shape that while clearly visible to most people, would be difficult to identify for those with color vision defects. The Farnsworth-Munsell 100 Hue Test is another widely used analysis that measures the ability to discriminate between subtle color changes. While there is no cure for the disorder, certain contact lenses and glasses may help users perceive colors more accurately.