Carrots and eyesight have often been linked. Although the idea is frequently thought of as simply an old wives' tale, carrots are said to improve eyesight when eaten. While carrots will not cure all eye ailments, they do have benefits to eye health because they contain large amounts of beta-carotene, an antioxidant and a pigment. The body converts beta-carotene to vitamin A, which is an essential nutrient for eye health.
Vitamin A deficiency is exceptionally harmful to eyes. A lack of vitamin A causes the chemical processes in the eyes to malfunction and the eyes' photoreceptors to deteriorate. If the deficiency is allowed to continue for long enough, it will cause blindness, and, in fact, is the leading cause of blindness in some underdeveloped countries. Vitamin A deficiency results in a condition called xerophthalmia, where the eyes cannot produce tears. It also may cause corneal ulcers.
In addition to beta-carotene, carrots contain lutein, another anti-oxidant. Lutein can help prevent macular degeneration because it creates greater pigment density in the eyes, helping to protect the retina. The anti-oxidants in carrots may also help prevent cataracts.
The connection between eating carrots and and an improvement in eyesight, however, is only valid if vitamin A is the problem. If poor eyesight is due to factors other than vitamin A deficiency, eating carrots will not improve the condition. It will help to prevent further eye problems, however.
Though carrots and eyesight have a strong connection, carrots also contain many vitamins and other nutrients that promote overall body health. For example, carrots contain vitamin E — which helps muscle health — and calcium, phosphorus, and magnesium, which are all important to healthy bone growth. Additionally, beta-carotene also helps prevent heart disease.
There are many fruits and vegetables that also contain beta-carotene and are thus healthy for the eyes. Mangoes, pumpkins, sweet potatoes, and apricots are just a few fruits and vegetables that contain carotene. Since beta-carotene is a pigment, it is easy to spot foods that are high in it. Basically, if the fruit or vegetable is a shade of orange, it has beta-carotene. Carrots, however, contain the most carotene of any fruit or vegetable, which is why carrots and eyesight are so often linked together.
Although a diet high in vitamin A is essential to good eye health, care should be taken not to eat too many fruits and vegetables high in beta-carotene. Too much of any nutrient will have negative consequences on the body. Although the side effects of too much carotene are generally benign, orange skin can be awkward and embarrassing.