Tests for peripheral vision utilize moving objects, and color vision is checked with a series of colored cards. A tonometer should be used on everyone over 35 or 40, to test for glaucoma. During this test, eye drops anesthetize the eye and a probe touches the eyeball to determine intraocular pressure. Tonometers that use a fast puff of air and do not require drops are sometimes used to screen large groups of people for glaucoma, but these devices are not as accurate. This is no longer considered necessary in all cases.
Enlarged pupils can temporarily inconvenience the patient by making bright light uncomfortable.
And the chemicals themselves may irritate the eye, making it difficult to determine the eye's normal functioning. Certain diseases especially cataract and retinal disease may necessitate drops. But the normal eye can be adequately examined without them. Besides diseases of the eye, the eye examination may also reveal the effects of diseases elsewhere in the body, including high blood pressure, diabetes, blood disorders, and tumors of the pituitary. Arthritis and other connective tissue disorders also affect the eye.