Vision vitamins are the nutritional elements that enhance eye sight. These include vitamin A, B6, C, selenium, trace elements such as magnesium and zinc among other nutrients. A variety of food containing vitamins include, among others oranges, carrots, pumpkin and leafy vegetables. Having enough of these food sources in the diet protects one from getting certain eye diseases such as cataracts and macular degeneration.
Vitamin A is important for continuous eye health. It facilitates better vision by influencing the synthesis of the pigmented rhodopsin found in the retina. It promotes good night vision or helps one see better in dim light. In addition, it ensures the cornea is kept moist by maintaining the integrity of related membranes.
It should be understood that vitamin A is not a single unit. Rather, it is made of several non-saturated hydrocarbons. These hydrocarbons include retinoic acid, retinol, retinal and other precursors known as carotenoids. Beta carotene is the most important of these carotenes. The retinal hydrocarbon reacts with a protein known as opsin to form rhodopsin. The resultant molecule helps in the achievement of scotopic (low light) and colour vision.
Lack of vitamin A causes many eye problems whose severity varies depending on the period of time one is affected and the extent of deficiency. Such a deficiency will be caused by inadequate amounts of vitamin A in the diet for a long time. This is called primary vitamin A deficiency. Its prevention entails frequent intake of carotenoid containing foods such as fruits, vegetables and dairy products.
Secondary deficiency is commonly the result of impaired absorption of lipids and decreased production and release of bile. The A vitamin is fat soluble and will therefore require that there are enough lipids for it to be adequately absorbed. Cigarette smoking and prolonged alcohol use are the other risk factors that have been identified as contributing to insufficiency of this vitamin.
One of the most initial manifestations of vitamin A deficiency is night blindness. This refers to impaired scotopic vision. With time, the condition may worsen and changes such as drying of the conjunctiva may occur. This happens because the normal tear secreting system is replaced by keratinisation. This is accompanied by formation of keratin plaques in the cornea which eventually gets eroded as more keratinisation leading to complete blindness.
The other vitamins play a relatively minor role. Vitamin C has antioxidant properties which help protect the eye from irradiation. It is also important in the maintenance of capillary integrity and normal pressure. The B6 vitamin maintains red cell structure and function and thus ensures that the retina functions optimally. Zinc takes part in the conversion of beta carotene to vitamin A.
The truth is that it is not possible to take all the vision vitamins on a daily basis. What is important is to ensure that one takes them as many times as possible within the week. Intake is determined by factors such as sex, age, pregnancy and lactation. Excessive of the vitamins may cause toxicity and due caution is, therefore, advised.
Vitamin A is important for continuous eye health. It facilitates better vision by influencing the synthesis of the pigmented rhodopsin found in the retina. It promotes good night vision or helps one see better in dim light. In addition, it ensures the cornea is kept moist by maintaining the integrity of related membranes.
It should be understood that vitamin A is not a single unit. Rather, it is made of several non-saturated hydrocarbons. These hydrocarbons include retinoic acid, retinol, retinal and other precursors known as carotenoids. Beta carotene is the most important of these carotenes. The retinal hydrocarbon reacts with a protein known as opsin to form rhodopsin. The resultant molecule helps in the achievement of scotopic (low light) and colour vision.
Lack of vitamin A causes many eye problems whose severity varies depending on the period of time one is affected and the extent of deficiency. Such a deficiency will be caused by inadequate amounts of vitamin A in the diet for a long time. This is called primary vitamin A deficiency. Its prevention entails frequent intake of carotenoid containing foods such as fruits, vegetables and dairy products.
Secondary deficiency is commonly the result of impaired absorption of lipids and decreased production and release of bile. The A vitamin is fat soluble and will therefore require that there are enough lipids for it to be adequately absorbed. Cigarette smoking and prolonged alcohol use are the other risk factors that have been identified as contributing to insufficiency of this vitamin.
One of the most initial manifestations of vitamin A deficiency is night blindness. This refers to impaired scotopic vision. With time, the condition may worsen and changes such as drying of the conjunctiva may occur. This happens because the normal tear secreting system is replaced by keratinisation. This is accompanied by formation of keratin plaques in the cornea which eventually gets eroded as more keratinisation leading to complete blindness.
The other vitamins play a relatively minor role. Vitamin C has antioxidant properties which help protect the eye from irradiation. It is also important in the maintenance of capillary integrity and normal pressure. The B6 vitamin maintains red cell structure and function and thus ensures that the retina functions optimally. Zinc takes part in the conversion of beta carotene to vitamin A.
The truth is that it is not possible to take all the vision vitamins on a daily basis. What is important is to ensure that one takes them as many times as possible within the week. Intake is determined by factors such as sex, age, pregnancy and lactation. Excessive of the vitamins may cause toxicity and due caution is, therefore, advised.
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