Color Blindness
When we see different colors, we are perceiving differences in the light that is reaching our eyes. The way we see different colors is something like the way we hear different sounds as being low or high. The colors of every rainbow always appear in the same order: red, orange, yellow, green, blue, indigo, and violet. The different colors in each part of the rainbow correspond to a different wavelength of light. Color blindness results from an absence or malfunction of certain color-sensitive cells in the retina. The retina is the nerve layer at the back of the eye that converts light into nerve signals that are sent to the brain. A person with color blindness has trouble seeing red, green, blue, or mixtures of these colors. Most color vision problems are inherited (genetic) and are present at birth. Other color vision problems are caused by aging, disease, injury to the eye (acquired color vision problems), optic nerve problems, or side effects of some medicines. Tests are used to measure the ability to recognize different colors with the most common test being the pseudoisochromatic plate test (also known as the Ishihara color test). The type of color vision problem you have can often be determined by which patterns you can and can't see in the various plates used for the test. Inherited color vision problems cannot be treated or corrected. Some acquired color vision problems can be treated, depending on the cause.
Proactive Eye Health
Good eye health and eye care are crucial to the value of sight. Be proactive in your eye health by taking a role in maintaining and protecting your sight, preventing common eye disorders, and treating problems early. Eye-care professionals, including ophthalmologists (medical doctors specializing in diseases and surgery of the eye) and optometrists recommend that everyone with visual or other eye signs or symptoms have their eyes checked. In people who have no symptoms, it is recommended that people over 40 have their eyes checked every two years and people over 60 have their eyes checked annually.
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