“When Elsie was only 18 months old she fell down and bumped the back of her head (or had measles, or whooping cough, or had a hard time cutting a tooth), and ever since then she has been cross-eyed.”
So Dr. Henry S. Gracile tells the story of the typical case of this kind in his article on “Hygiene of the Eye.” He goes on to explain:
That the bump or the measles didn’t cause the cross eyes. Some children are born with a tendency to cross eyes. By unconscious effort they keep the eyes straight for a year or more, until some accident or bump or illness weakens control and the eye diverges.
There are little muscles attached all over the outside of the eye-ball which moves it in various directions. If one of these is stronger or weaker than the others, the eyeball is pulled out of line.
It takes long and patient training to restore the condition to normal.
The proper procedure is as follows:
In most cases the vision of the affected eye is weak or abnormal (due to astigmatism). The first thing to do, then, is to discover just the nature of this and to put on glasses to correct it. Since the condition becomes evident at about the age of two years, and since a child of that age can give no aid in the fitting of glasses, drops have to be put in the eye to put the muscles at rest, and exact measurements of the defect made.
With the glasses properly adjusted the child must be taught to see all over again. The weak eye must be especially trained. The good eye must be covered for an hour or two a day, and the weak one improved by making it do all the work of vision.
Exercises to train the weakened muscles and make them converge are also employed.
Even with all the methods employed improvement comes only with time, and if results are obtained by the end of two years it may be counted soon enough. So all the cross-eyed child’s attendants must persist patiently in the work.
It is worth doing well because in 85 per cent of all cases the squint can be corrected by these methods of training.
But even when success is at hand up to the age of 18, the eyes may become crossed when the glasses are removed at night or when the child is tired.
In the remaining 15 per cent of instances, the methods described above are not sufficient. Then the little muscles must be shortened or lengthened by a surgical procedure. It may be advisable to do this as early as four years of age or less.