ABOUT CVD

WHAT IS COLOR VISION DEFICIENCY (CVD)?

CVD is the inability to distinguish between certain shades of color.

what percentage of people have COlor vision deficiency?

It is estimated that 1 in 12 men (8%) and 1 in 200 women (.5%) have some form of color vision deficiency.

Why is it much more likely for men to suffer from color vision deficiency than women?

Since men have (XY) chromosomes, it only needs one (X) chromosome to be affected, while women having (XX) chromosomes, need both of their chromosomes affected to have CVD.

what are the causes of color vision deficiency?

Color vision deficiency is caused by mutation to your genes. In most cases, the condition is there from birth. When you have CVD, it’s usually because your eyes don’t contain the normally functioning cones in the retina needed for full color vision. Additionally, there are some conditions of CVD that are not caused by gene mutations, which are referred to as acquired color vision deficiencies. They can be caused by other eye disorders, such as diseases involving the retina or the optic nerve with retinal damage, brain trauma and/or vitamin deficiency.

HOW IS CVD DIAGNOSED?

There are numerous tests performed to search for color vision deficiency. One of the most popular being the Ishihara Plate test.

What is the ishihara test?

Dr. Shinobu Ishihara, a professor at the University of Tokyo, developed a series of plates which assembled a series of color dots with a number in the middle made with different colored dots. Ishihara plates can help diagnose red-green color vision defects but doesn’t test blue-yellow defects. This test has no associated risks, and no special preparation is necessary.

is THERE A CURE FOR Cvd? TREATMENT OPTIONS?

Currently, there is no cure for color vision deficiency. The severity and type of color blindness varies widely, ranging from total color blindness and red-green deficiency to blue-yellow deficiency. Within these types, there are also different subtypes and levels of severity. Diagnosing children early may help parents and teachers to aid children with coping mechanisms. Special filtered lenses may also help people with red–green color deficiency.

are there different types of color vision deficiency?

Yes, there are actually 7 different types of color vision deficiency: four different types of red-green, two types of blue-yellow, and Monochromacy, in which one can only see black and white, and affects less than .00003% of those with CVD.

what are the differences between the 4 red-green types?

Protanopia – red looks dark grey, some shades of orange, yellow and green look yellow.
Protanomaly – orange, red and yellow look greener, and colors are less bright.
Deuteranopia – reds may look brownish-yellow, and greens may look beige.
Deuteranomaly – the most common of the four, it makes green and yellow look more red. Blues and purples are often confused as well.