Cancer is an aggressive growth of mass that destroys healthy tissue. The condition can develop in any organ or affect any function of the body due to an underlying genetic mutation. Eye cancer is one of the extremely rare forms of cancer that could develop in the eyeball, eyelids, or tear ducts. The condition is usually detected during a routine eye checkup or if one notices any of the following early signs of eye cancer:

Changes in vision
One of the first signs of eye cancer is changes in vision. As the cancer grows in the eye, it affects the optic nerves that process all visual information. So, one may experience light flashes, floaters, blurry, or even double vision when the field of view is affected. Cancer damages healthy cells in the eye, but the intensity of these symptoms can vary from person to person.

Pigmentation or spots
One may notice a small dark spot growing in their eyes. This type of pigmentation indicates a type of eye melanoma that starts around the iris. Dark spots may also develop in the conjunctiva and grow as cancer spreads. Upon noticing such changes, one should consult an ophthalmologist to determine the precise cause.

Bulging and swelling
Bulging of the eye can often be confused with infections or inflammation. But, if one notices a small, raised lump developing on the eyeball in the center of the eyelids, one should get it examined by an eye specialist. These lesions can grow and begin affecting normal vision. The extent of swelling can vary from person to person, depending on the type of eye cancer.

Excessive tearing and bloody tears
The uncontrolled formation of tears is a sign of tear duct damage. This could develop due to cell damage caused by cancer; however, further eye tests and diagnosis is necessary to confirm the issue. One might also experience bloody tears brought on by bleeding tear ducts. 

Changes in eyeball movement
Usually, both eyeballs move at the same time and are controlled by the brain. So, if one notices any unnatural movement in one or both eyeballs, it is better to consult a doctor. Movements can be random or follow a pattern that seems unnatural. This can happen due to nerve damage associated with cancer. One may even notice changes in the shape of the pupil, as it can grow or shrink in size or even lose its shape leading to visual deformity when dealing with eye cancer.

Persistent stye-like symptoms
Styes are red bumps that develop on the edge of the eyelids when oil-producing glands become infected and cause the skin to bugle and take on a red hue. Stye is a common condition that can develop on the inside or outside of the eyelids. However, a stye that does not heal with proper treatment could be a sign of a serious underlying issue like cancer. As cancer affects immunity and the body’s ability to rejuvenate damaged cells, it could be the reason behind a persistent stye.

Pain in the eye
Although rare, some people might also experience persistent pain in the eye without other symptoms. This could be an early warning sign of eye cancer. However, one should book an eye exam if they notice any changes in the appearance of the eyes or eyesight.