How Do Brain Tumors Affect the Eyes? Vision Changes

Brain tumors can lead to vision changes such as:

• Blurred or double vision
• Narrowing of your field of vision
• Blind spots
• Difficulty controlling eye movements
• Unusual eye movements such as flickering of the eyes
• Increased sensitivity to light
• Head tilt (caused by trying to see things out of the corner of the eye)
• Sudden blurring of vision that may be triggered by coughing or bending down
• Proptosis (bulging of the eyes)
• Loss of vision

In most people, initial ocular symptoms are progressive loss of vision with or without damage to the optic nerve. Some tumors may cause acute visual loss as the presenting symptom.

While there are many potential causes for eye-related problems, symptoms that occur suddenly may indicate a blood clot or infections such as meningitis or encephalitis.

Consult your doctor regarding your symptoms. If a brain tumor is suspected, your doctor can order tests and devise an appropriate treatment plan.

The three most common types of brain tumors in adults that can cause vision problems include:

• Pituitary adenoma: Can cause a type of partial blindness in which vision is lost in the outer half of both the right and left visual field (bitemporal hemianopia)
• Meningioma: Can cause partial or complete loss of vision in one eye; other symptoms may include blurred or double vision
• Craniopharyngioma: Can cause a defect in the visual field and an initial decrease in visual acuity (ability of the eye to identify shapes and the details of objects at a given distance)

Brain tumors can cause vision problems as pressure is exerted on certain areas of the brain:

• Occipital lobe: Part of your brain responsible for processing what you see. Tumors in this region of the brain can lead to several vision problems.
• Brain stem: Tumors in this area could result in double vision.
• Neural connections: If the tumor invades any of the neural connections between your eyes and your occipital lobe, it can cause blind spots.
• Optic nerve: If the tumor exerts pressure on your optic nerve or causes the optic disc (back of the eye) to swell (papilledema), it can lead to vision loss and even blindness as the tumor grows.

Symptoms of brain tumors depend on their location. Besides vision problems, other common symptoms of brain tumors may include:

• Persistent nausea and vomiting
• Extreme or sudden drowsiness
• Tinnitus or hearing loss
• Unexplained bodily twitches
• Seizures 
• Confusion
• Loss of balance
• Numbness or weakness in certain parts of your body
• Difficulty concentrating
• Changes in personality or behavior
• Changes in mental abilities or memory
• Changes in senses
• Changes in speech, writing, or drawing
• Changes in sleep patterns

If you have vision changes caused by a brain tumor, your ophthalmologist may be the first to diagnose it. Tests that may be ordered include:

• Refractive error screening and checkup for intraocular pressure
• Neurological exam to check your visual reflexes, hearing, balance, coordination, strength, and reflexes
• Imaging tests such as magnetic resonance imaging, computed tomography, and positron emission tomography to help assess the tumor
• Biopsy, which involves collecting and testing a sample of brain tumor tissue and can be performed as part of surgery to remove the brain tumor

Your doctors will plan treatment based on the type, size, and location of the brain tumor as well as your overall health.