Colour Vision Deficiency (CVD)

The illustration above shows a common color vision screening test.

Colour vision deficiency (CVD) is the inability to distinguish between certain colours. It occurs when the eye’s cone cells, responsible for detecting red, green, or blue light, do not function properly.

There are several types of CVD, mainly categorized into red-green, blue-yellow, and monochromacy (complete colour blindness).

Red-Green Colour Deficiency (Most Common)

· Caused by malfunctioning red or green cone cells in the retina.

· Difficulty distinguishing between reds, greens, and colour combinations involving these shades.

Blue-Yellow Colour Deficiency (Less Common)

· Occurs when the blue cone cells do not work correctly.

· Trouble differentiating between blue and yellow hues.

Monochromacy (Rare)

· Also known as complete colour blindness.

· Vision is limited to shades of gray or a limited colour spectrum, depending on the type.

CVD is usually inherited but can also develop due to aging, chronic illnesses, certain medications, eye diseases, injuries, or exposure to environmental chemicals. While there is no cure, prescription colour filter lenses can help enhance colour perception.

Visit us for a free consultation to identify your type of colour deficiency and try sample prescription colour filter lenses. Walk-ins are always welcome!