Nowadays defective vision is a common problem and it happens mostly due to reading in bad light (either too dim or excessively bright), excessive reading, reading in moving trains, buses or cars, watching too much television, seeing too many films, and following faulty food habits. Hence, people wear spectacles to rectify all cases of defective vision caused by permanent changes in the eyes.

Persons who are prescribed glasses are told that they should avoid taking them off because of the danger of eyestrain and that they should always look straight through the centre of the lens. Moreover, the use of glasses results in a reduction of blinking which is a movement intended to assist and preserve eyesight. However, wearing glasses for many years results in stiff, dull-looking eyes without any sparkle.

Causes of Defective Vision:
The three chief causes of defective vision are mental strain, wrong diet, and improper blood and nerve supply.

Mental Strain: It is the cause of ad defects of vision, putting corresponding physical strain on the eyes, their muscles and nerves.

Improper Diet: Most of the diseases affecting the eyes are symptoms of a general toxemic condition of the body due mainly to excessive starch, sugar and protein ingestion. The muscles and blood vessels surrounding the eyes share in the clogging process taking place over the body due to improper metabolism caused by an imbalanced and too-concentrated diet.

Improper Blood and Nerve Supply: The eyes need to be properly supplied with blood and nerve force for proper vision. Any factor capable of interfering either with the blood-vessels or with the nerves of the eyes could cause defective vision.

Treatment of Defective Vision by Natural therapy:
Eye Exercises:: The following exercises will loosen the strained and contracted muscles surrounding the eyes:

(i) Keep your head still and relaxed. Gently move the eyes up and down six times. Repeat the same movement twice or thrice at two-second intervals. The eyes should move slowly and regularly as far down as possible and then as far up as possible.

(ii) Move the eyes from side to side as far as possible, without any force or effort six times. Repeat two or three times.

(iii) Hold the index finger of your right hand about eight inches in front of the eyes, then look from the finger to any other large object ten or more feet away the door or window will do. Look from one to the other ten times. Do this exercise fairly rapidly.

(iv) Move the eyes up gently and slowly in a circle, then move them low in the reverse direction. Do this four times in all. Rest for a second and repeat the movements two or three times, using minimum effort. All eye muscle exercises should be performed while seated in a comfortable position.

Neck exercises: : the following are the varios neck exercises for curing the problem of defective vision. they are:

1.One should rotate the neck
(a) in circles and semi-circles,
(b) move the shoulders clockwise and anti-clockwise briskly, drawing them up as far as possible several times,
(c) allow the head to drop forward and backward as far as possible,
(d) turn the head to the right and left as far as possible several times. These exercises help to loosen up contracted neck muscles, which may restrict blood supply to the head.

2. Sun gazing: Sit on a bench facing the sun with your eyes closed and gently sway sideways several times for 18 minutes. Open the eyes and blink about 10 times at the sun and look at some greenery. This helps shortsight and is good for inflamed eyes.

3. Splashing: Splash plain, cold water several times on closed eyes. Rub the closed lids briskly for a minute with a clean towel. This cools the eyes and boosts blood supply.

4. Palming: Sit comfortably in an armchair or on a settee and relax with your eyes closed. Cover your eyes with your palms, right palm over the right eye and the left over the left eye. Do not, however, press down on the eyes. With your eyes completely covered in this manner, allow your elbows to drop to your knees, which should be fairly close together. With your eyes closed thus, try to imagine blackness, which grows blacker and blacker. Palming reduces strain and relaxes the eyes and its surrounding tissues.

5. Swinging: Stand with your feet 12 inches apart, hands held loosely at the sides, the whole body and mind relaxed. Gently sway your body from side to side, slowly, steadily with the heels rising alternatively but not the rest of the foot. Image that you are the pendulum of a clock, and move just as slowly. Swinging should be done in front of a window or a picture. You will see the object moving in the opposite direction of your swing. This must be noted and encouraged. When you face one end of the window or object, blink once. This exercise has a very beneficial effect upon the eyes and nervous system.

Treatment of Defective Vision by Diet:
Natural, uncooked foods are the best diet for the treatment. These include fresh fruits such as oranges, apples, grapes, peaches, plum cherries, green vegetables like lettuce, cabbage, spinach, turnip tops, root vegetables like potatoes, turnips, carrot, onions and beetroots, nuts, dried fruits and dairy products.

Cereals are also necessary, but they should only be consumed sparingly. Genuine whole meal bread is the best and most suitable. Naans, cakes, pastries, white sugar, white bread, confectionery, tea, coffee, etc. together with meat, fish, or eggs, do not work comfortably well, with the digestion of the body.

The value of vitamin A for improving vision must be stressed. The intake of sufficient quantities of this vitamin is essential as a safeguard against or treatment of defective vision or eye disease of any kind. The best sources of this vitamin are cod liver oil, raw spinach, turnip tops, cream, cheese, butter, egg yolk, tomatoes, lettuce, carrot, cabbage, soya beans, green peas, wheat germ, fresh milk, oranges and dates.

Treatment of Defective Vision by Magnetic Therapy:
Many cases of weak eyesight especially in children and young persons have responded well to Magneto therapy. The mode of application of the magnets is as follows: Apply the North Pole SEM to the right hand and a South Pole CCM first to the left eye and then to the right eye 10 minutes each time. During the entire application, magnetic application to the hand will be unchanged for 20 minutes.

Yogic Exercises for the treatment of Defective Vision:
The four yogic exercises prescribed for strengthening the optic nerve known as `trataka` should be practised daily. Certain yogasanas such as bhujangasana, shalabhasana, yogamudra, paschimottan asana and kriyas like jalneti are also beneficial for the eyes.