CATARACT.—This is an opacity of the crystalline lens or its capsule. The lens is not clear and bright and keeps the light from going through it. Then it is called opaque.
SENILE CATARACT.—The vast majority of these cataracts are found after the age of fifty. They simply come without any known cause. Of course, injury can cause a cataract and it is then called traumatic cataract.
Symptoms of Senile (Old Age) Cataract.—Blurred vision, flashes and streaks of light, dark spots, double vision. There is no pain. Eye strain due to imperfect sight. Sometimes the first symptom is ability to read without glasses (second sight). This is due to the increased refractive power of the lens from swelling. The lens looks a little whitish through the pupil opening and looks more so as time goes on.
Course.—The progress is slow. It usually takes a number of years before it is "ripe" for operation. They may remain in the same condition sometimes. In this kind of cataract both eyes are affected sooner or later, although one eye may be fully matured before the other is much changed.
The result of an operation depends upon the condition of the eye. The eye should be free from evidence of disease. "The anterior chamber should be of normal depth. The pupil should react to light. There should be a homogeneous (all alike) white or gray opacity immediately back of the pupil, with no shadow from the edge of the pupil (except in cases of sclerosis, already mentioned). A candle carried on all sides of the patient while the eye is fixed, should be properly located by him. The tension of the eyeball should be normal."
The operation is very frequently done and it is very successful. The patient should be ready and willing to place himself in the charge of the operator and do as he says.
SYMPATHETIC INFLAMMATION OF THE EYE.—(Sympathetic Ophthalmia.)—A condition in which the healthy eye becomes the seat of a destructive inflammation transferred from the other eye which has been the subject of a similar inflammation usually following a perforating injury of the eyeball. The injured eye is called the exciting eye; the other, the sympathetic eye.
This is a rare disease, but it may occur when one eye is injured or diseased and on the first indication of trouble in the injured eye the other eye should be closely watched for symptoms of sympathetic trouble so that if can be removed.
Symptoms in the Exciting Eye.—This is more or less congested and painful; when pressure is made upon the upper lid, it shows tenderness. The tension is not as strong; the pupil may be blocked with an exudate.
In the Sympathizing Eye.—There is an inflammation involving the choroid, ciliary body and iris. There is pain, tenderness, small blocked pupil and sight is poor.