Some eye symptoms are manifestations of a brain tumor. A tumor in the brain can cause symptoms either because of raised pressure in the cranial cavity or because of direct pressure by the tumor on the adjacent structures above and behind the eyes.
The tumor can compress the arteries, veins and nerves meant for the eyes and produce symptoms depending on the structures affected or damaged.
Apart from the eye symptoms, the brain tumor also causes headache, seizures and loss of consciousness.
If you are having problems with your eyes you should see your doctor. This is particularly important if your sight seems to be failing and glasses are not helping. Other problems include blurred vision, floating shapes, tunnel vision, or a loss of vision that comes and goes. Sometimes opticians pick up these problems. It is possible to detect raised intracranial pressure during an eye examination.