Key Difference: Glaucoma is a condition that leads to a slow vision loss in the eyes. It can occur in one or both eyes, though it does not spread from one eye to the other. Cataracts, on the other hand, are a condition when the lenses of the eyes tend to become cloudy and vision becomes blurry.

One of the main differences between glaucoma and cataract is the fact that cataract occurs primarily due to old age, while glaucoma is a disease that can occur anytime; though it also primarily affects older people. As we get older, the lenses in our eyes tend to get thicker and get discolored. This is known as a cataract, whereas glaucoma is a condition that occurs when there is damage to the optic nerve, which is most commonly caused by increase pressure in the eye.

The optic nerve is a bundle of more than 1 million nerve fibers that connect the retina to the brain. The retina is the light-sensitive tissue at the back of the eye, on which the eye projects the light it absorbs. The retina then sends the image through the optic nerve to the brain, where the brain interprets the image. However, if the optic nerve is damaged then there will be no communication between the eye and the brain.

Glaucoma is a condition that leads to a slow vision loss in the eyes. It can occur in one or both eyes, though it does not spread from one eye to the other. In this condition, there is slow damage to the optic nerve which causes the person to initially lose peripheral vision, leading them to view things as if they are looking at things through a tunnel. Untreated glaucoma will eventually lead to total vision loss.

It is hard to initially diagnose glaucoma, as it is undetectable by the patient until they start losing their peripheral vision. Prior to that, there are practically no symptoms to indicate to the patient that they may be suffering from it, no pain either. Hence, early detection is key in cases of glaucoma, as steps can be taken to limit vision loss in the eyes. Once the damage to the optic nerve has spread, it cannot be reversed. However, treatments can be undertaken to slow down or limit vision loss.

Cataracts, on the other hand, are a condition when the lenses of the eyes tend to become cloudy and vision becomes blurry. The lenses in the eyes are made up of protein, however, over time, the protein tends to clump thus reducing the light that passes through the eyes and reducing the vision.

Cataracts usually occur due to age, as the wear and tear that the eyes endure over the years makes the lenses susceptible to clumping. However, certain factors, such as smoking or already having diabetes or glaucoma may increase the risk of developing cataracts.

The most noticeable symptom of cataracts is the cloudy vision. Patients may also experience double vision, glare, or halos. They may also have trouble viewing color. However, if these conditions get worse enough to disrupt day to day life, then one can opt for a surgery to replace their cloudy lenses with clear plastic ones, which will allow the light to pass through to the eye once again and improve vision.

Comparison between Glaucoma and Cataract:

Reference: Nei.nih.gov (Glaucoma and Cataract), Glaucoma.org, Amsurgcontent.com
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