Hesperian Health Guides

Illnesses that Can Affect the Eyes

In this chapter:

Some infections or illnesses affecting the whole body can harm the eyes. When someone has eye problems, it is wise to consider if the cause could be another illness.

Tuberculosis can infect the eyes and cause redness or poor vision. Most often, signs of tuberculosis will appear first in the lungs or other parts of the body.

HIV and AIDS: Eye problems and loss of vision in people with HIV are prevented by treatment with HIV medicines, called ART. Get tested so you can start treatment if you need it.

Herpes (cold sores) occasionally spreads to the eye, causing an ulcer of the cornea with pain, blurred vision, and watery eyes. Antiviral medicines are helpful. Do not use steroid eye drops—they make the problem worse.

Problems in the liver: Jaundice, when the white part of the eye is yellow (or the skin of a light-colored person gets yellow), can be a sign of hepatitis.

Diabetes and high blood pressure

People with diabetes may develop vision problems. As the disease advances, diabetes can damage their eyes (a serious condition called diabetic retinopathy). Without treatment, diabetes can lead to blindness. Blurred vision can be an early sign that blood sugar is high and a person may have diabetes. If someone with blurred vision also is very thirsty and has to urinate a lot, it is likely they have diabetes. Inexpensive tests can let them know for sure.

Help people with diabetes get treatment to bring down their blood sugar levels and encourage them to visit an eye specialist once a year to check their eyes for damage from diabetes. Eye disease from diabetes can be treated if found early.

High blood pressure can affect the eyes and vision by damaging the blood vessels inside the eye. Checking blood pressure during health care visits is the best way to know if it is too high. Preventing and treating high blood pressure will help protect the eyes.

River blindness (onchocerciasis)

The black fly has a humped back like this but is actually much smaller, like this.
NWTND eye Page 26-1.png
 a the humped back of a very small fly

This disease of the eyes and skin is becoming less common. It is still found in parts of Africa, Yemen, and a few communities in the Amazon region of South America. River blindness is caused by tiny worms that are carried by black flies. The worms get inside a person when an infected fly bites him.

  • Itchy skin and rash
  • 2 to 3 cm lumps you can feel under the skin

Without treatment, the skin gradually becomes wrinkled and loose. White spots and patches may appear on the front of the lower legs.

The illness can lead to eye problems and sometimes blindness. First there may be redness and watery eyes, then signs of iritis may follow.


The medicine ivermectin treats river blindness. Where ivermectin is given every 6 months or once a year as part of community-wide campaigns, fewer people get the disease and it may disappear from the region.

  • These black flies breed in fast-running water. Clearing brush from the edges of stream and river banks helps reduce their number.
  • Avoid sleeping outside, especially in the daytime when the flies bite most.
  • Cooperate with programs working to lower the number of black flies and with the health workers giving ivermectin to the whole community to prevent new cases.

Early treatment prevents blindness and reduces spread of the disease.

This page was updated:10 Jan 2020