About 50 per cent of the populations in industrialised countries use lenses (spectacles or contact lenses). While it may be true that the use of aids is not always essential, it is certain that a large number of school children lag behind for lack of proper corrective lenses. This is a barrier when reading out of textbooks and whiteboards (black boards)

As with any other human body organ, the eyes need to be appropriately nourished. In the case of the eyes, although they are highly complex, delicate and their function is fundamental, they do not make many nutritional demands, as indicated before, and they "need very little.”

Now the fact that they need very little does not indicate that the lack of essentials will not affect them. In fact, the opposite is true. Commonly, many people who change from a diet low in vegetables to one containing more report feeling better in all areas:

They experience an increase in energy and vitalityTheir skin and hair take on a new shine and their nails become strongerTheir digestion become easier and intestinal functions are more regular.Their night rest improves and becomes restorative.They suffer less from infectious diseases, such as flu and coldsTheir breath becomes cleanerAnd their eye sight improvesAnd this is logical, as nutritional imbalance caused by a deficient diet affects all body organs and more especially those of more sensitive nature.

An appropriate diet may also protect against cataracts.

The lack of carotenoids (provitamin A) is especially noticeable in car drivers who suffer from so-called night blindness and lack of adaptability to change in light.