The pupil reacts promptly to light, contracting in bright settings and expanding in darker ones.
Changes in the color of the sclera (the white part of the eyes) can indicate an issue. A red and bloodshot eye may be caused by excessive alcohol or drug use, as well as irritation or infection that usually resolves within a few days.
However, in severe cases, a red eye could indicate glaucoma, a serious condition that can lead to blindness. When the sclera turns yellow, it is a clear indication of jaundice and liver disease. The underlying reasons for jaundice can vary widely.
A blood-red spot on the white of the eye may appear scary, but it is usually caused by a small burst blood vessel.
A white or grey ring encircling the cornea is commonly associated with high cholesterol and an increased risk of heart disease. It can also indicate alcoholism and is sometimes present in older people's eyes, which is why it is called arcus senilis medically.
A yellowish, fatty lump that appears on the eye's white is called pinguecula, a small deposit of fat and protein that can be easily treated with eye drops or removed by a simple operation.