Symptoms

You may have a color vision deficiency and not know it. Some people figure out that they or their child has the condition when it causes confusion — such as when there are problems differentiating the colors in a traffic light or interpreting color-coded learning materials.

People affected by color blindness may not be able to distinguish:

• Different shades of red and green
• Different shades of blue and yellow
• Any colors

The most common color deficiency is an inability to see some shades of red and green. Often, a person who is red-green or blue-yellow deficient isn't completely insensitive to both colors. Defects can be mild, moderate or severe.

When to see a doctor

If you suspect you have problems distinguishing certain colors or your color vision changes, see an eye doctor for testing. It's important that children get comprehensive eye exams, including color vision testing, before starting school.

There's no cure for inherited color deficiencies, but if illness or eye disease is the cause, treatment may improve color vision.