Adults who become blind after several decades of normal or at least useful sight represent a different problem. Their psychological and practical difficulties are manifold. The sudden onset of blindness is a terrifying experience. Apart from the helplessness and inability to become mobile there is a horror of incapacity, accompanied by the realization that without help the sufferer is completely isolated, socially and physically. The adult who becomes blind is liable to become deeply embittered, much more so than if he or she had lost a limb. The loss of a limb is measurable and understandable. Sudden blindness is far more abstract, for a while incomprehensible. And because the loss of sight is rarely complete, the patient lives in hope of cure. Bouts of depression alternate with pitiable optimism. If the patient is rich, or if the public health authority permits, he or she will seek charlatan as well as professional advice. He or she will become subject to advice from the market place, faith healers and the like. Newly blind people will sometimes travel grêat distances to seek remission. If religious they will seek shrines and miracles (and some people become religious when they become blind). Equally they will alter their philosophy of life, to purge that which is supposed to have robbed them of their sight. Read the rest of this entry »
There is a well-known story about Noel Coward. The dramatist was out walking with two small children one day when the party came into view of two dogs engaged in the act of copulation. `Uncle Noel, what are they doing?’ cried one of the boys. ‘It’s perfectly obvious,’ replied Coward. ‘Can’t you see? The dog in front is blind, and the dog behind is pushing him to St Dunstan’s!’
The subtlety of this anecdote lies in the substitution of one taboo subject by another. Historically, blindness has carried different cultural connotations. Among the ancients it was often considered as a punishment meted out by the gods. In the best known of the Greek myths, Oedipus gouges out his own eyes in a hubristic act of self-inflicted retribution. In modern times blindness is more simply perceived as a misfortune. Read the rest of this entry »
It is also obvious that the method must have prevented other errors of refraction, a problem which previously had not even been seriously considered, because hypermetropia is supposed to be congenital and until not long ago astigmatism was also supposed to be congenital in the great majority of cases. Anyone who knows how to use a retinoscope, however, can demonstrate in a few minutes that both of these conditions are acquired; for no matter how astigmatic or hypermetropic an eye may be, its vision always becomes normal when it looks at a blank surface without trying to see. Read the rest of this entry »
To repeat a very important principle: you cannot see anything with perfect sight unless you have seen it before. When the eye looks at an unfamiliar object it always strains more or less to see that object, and an error of refraction is always produced. When children look at unfamiliar writing or figures on the blackboard, distant maps, diagrams, or pictures, the retinoscope always shows that they are myopic, though their vision may be absolutely normal under other circumstances. The same thing happens when adults look at unfamiliar distant objects. When the eye regards a familiar object, however, the effect is quite different. Not only can it be regarded without strain, but the strain of looking at unfamiliar objects later is lessened. Read the rest of this entry »
A shortsighted young woman, to take the opposite of this case, had a passion for mathematics and anatomy and excelled in those subjects. She learned to use the ophthalmoscope as easily as the farsighted girl had learned Latin. Almost immediately she saw the optic nerve and noted that the center was whiter than the periphery. She saw the light-colored lines, the arteries; and the darker ones, the veins; and she saw the light streaks on the blood vessels. Some specialists never become able to do this, and no one could do it without normal vision. Her vision, therefore, must have been temporarily normal when she did it. Her vision for figures, although not normal, was better than for letters. Read the rest of this entry »
Defective vision, as I have said, is the result of an abnormal condition of the mind. Glasses may sometimes neutralize the effect of this condition upon the eyes, and by making a person more comfortable may improve his mental faculties to some extent; but we do not alter fundamentally the condition of the mind, and by confirming it in a bad habit we may make it worse. Read the rest of this entry »
In order to fully understand how a contact lens works, you should first have a basic knowledge and appreciation of the structure and workings of your eyes.
Anatomy of the Eye
The eye is often compared to a camera. There are many similarities, but the eye is actually much more complex and miraculous: it focuses and adjusts to light automatically, and the film never runs out. Moreover it picks up a constant stream of images, in contrast to the single image that registers on each frame of film; it is self-cleaning and “develops” film instantly —all in the space of a one-inch-diameter globe! Read the rest of this entry »
