Visual Field Defects

A visual field defect is the medical name for losing an area of your vision. Your visual field is everything you can see without moving your head. It includes what’s directly in front of you (your central vision) and off to the sides (your peripheral vision).

These defects are different from refractive errors like being nearsighted or having astigmatism. Visual field defects affect only part of your vision. A refractive error will make everything you see blurry.

Visit an eye doctor or go to the emergency room as soon as you notice any changes in your vision, especially if they happen suddenly.

Types of visual field defects

There are two main types of visual field defects:

• Scotoma: This is a blind spot. You’ll lose sight in one small part of your vision.
• Anopia: This is a larger area of vision loss. It affects bigger portions of your visual field in one or both eyes.

Specific examples of visual field defects include:

• Central scotoma: This is a blind spot in the center of your vision.
• Tunnel vision: This is losing your peripheral vision. You’ll only be able to see what’s right in front of you.
• Quadrantanopia: This is vision loss in one quarter of your visual field.
• Monocular/unilateral vision loss: This happens when you lose sight in one eye.
• Bitemporal hemianopia: This is losing the outer half of your vision in both eyes. You won’t be able to see out of the left half of your left eye or the right half of your right eye.
• Homonymous hemianopia: This happens when you lose the same half of vision in both eyes. You’ll lose sight in the right or left halves of both eyes at the same time.
• Altitudinal: This happens when you lose vision above or below a horizontal line in your sight. It usually happens in one eye.

What are the most common causes of visual field defects?

Lots of issues can cause visual field defects. They happen when something damages or disrupts part of your visual system, including your:

• Eyes
• Retinas
• Optic nerves
• Brain

Some causes include:

• Glaucoma
• Macular degeneration
• Detached retinas or other retina problems
• Optic nerve damage
• Tumors in your eye or brain
• Strokes
• Transient ischemic attacks
• Multiple sclerosis (MS)
• Seizures

Traumas that damage your visual system can lead to visual field defects. Examples include:

• Eye injuries
• Head injuries
• Concussions
• Traumatic brain injuries (TBIs)

How are visual field defects treated?

Treatments for visual field defects vary. What’s best for you depends on what’s causing the issue. Your eye doctor will suggest treatments that manage the cause. They’ll let you know what you’ll need to get your visual system working like it should again.

When should this be treated by a doctor or healthcare provider?

All visual field defects need diagnosis and treatment. This is not only to restore your usual vision, but also to get the underlying cause diagnosed. Some issues that cause them can be very serious.

Visit an eye doctor if you notice any changes in your eyes or vision. Go to the emergency room if you experience sudden vision loss. This can be a sign of serious issues like a detached retina or stroke.

If possible, don’t drive yourself to the ER or eye doctor. Driving with vision changes can be dangerous.