Eye cancer is uncommon, but it can develop in both adults and children while manifesting symptoms similar to other eye problems. The symptoms of eye cancer include a number of conditions that can also be attributed to other causes. These include poor or blurred vision, loss of vision in the afflicted eye, a change in the shape of the pupil, dark spots visible on the surface of the eye, or sensations of flashing lights.

There are a number of reasons for vision problems, and eye cancer is only one of them. Floaters, or spots drifting across the field of vision, and flashes of light can occur without changes in a person's clarity of vision. A loss of sight, either complete or in a certain area within the field of vision, can be another of the symptoms of eye cancer. There can also be a noticeable physical change in the eye, including changing size in the pupil, bulges, or a change in the way the eye sits or moves.

One of the most common symptoms that indicate something is wrong within the body is extremely rare in cases of eye cancer. There is almost never pain associated with symptoms of eye cancer, and when it is present the cancer has usually already spread to a large area outside of the eye itself. In these very rare cases, there is often a noticeable change in the position of the eye within the socket.

Eye cancer, also known as eye melanoma or ocular melanoma, develops when there is an error in the DNA of a healthy eye. These errors instruct the mutated cells to continue to grow; the cells then accumulate in the eye and symptoms begin to develop. Most commonly, the cancer is found in the vascular layer of the eye near the retina, but can also develop in the outer layer in the front of the eye. These types of cancers in the outer eye are exceedingly rare.

It is just as important to understand that some of these conditions are caused by something much less serious, and are not necessarily symptoms of eye cancer. Blurred vision and floaters can simply be a part of the natural aging process, but it is never a bad idea to have any changes in vision checked by a healthcare professional. Diagnosis often consists simply of an eye exam, as eye cancer can often be detected with hand-held instruments and other microscopes designed to look into the eye.