This is a state of impaired vision, accompanied with a greenish discoloration of the pupil of the eye. The patient complains of gradually increasing dimness of sight, attended with more or less rheumatic pain over the eyebrow, and visions of black spots, and flashes of light. The pupil is dilated, and moves sluggishly; the eye feels hard, and the blood-vessels often appear dilated and varicose. The patient is generally from forty to sixty years of age, and the disease appears to partake of the nature of senile degeneration. It may be distinguished from Cataract, by the greenish colour, and indistinct nature of the opacity; which resembles "the reflection of the sun's rays from a muddy pool," and by its being seen deep in the eye; whereas, in Cataract, a definite, whitish, opake body is seen immediately behind the pupil. The opacity disappears, moreover, in Glaucoma, when looked at sideways, which is not the case in Cataract. Vision is assisted by a strong light in Glaucoma; but the reverse in Cataract.

Treatment

If the complaint is the result of approaching age, no other treatment would be useful beyond abstaining from using the eyes, and from anything likely to disorder the health. But if it began suddenly, with acute symptoms of a gouty character, as it does sometimes, it must be treated with cupping at the back of the neck, blisters behind the ears, and purgatives.