Vision and perception after brain injury

How traumatic brain injury and stroke affect seeing and making sense of what you see - and what recovery looks like.

Vision problems after brain injury are surprisingly common - and often overlooked because they don’t show up in a basic eye test. The eyes themselves may be working fine; it’s the brain’s ability to process what they send that’s been disrupted.

How vision works in the brain

The optic nerves carry signals from both eyes to the back of the brain (occipital cortex). From there, the signal splits into two streams:

“What” stream (temporal lobe) - identifies what you’re looking at: faces, words, objects.
“Where/how” stream (parietal lobe) - tracks where things are and guides reaching and movement.

Damage anywhere in this chain can cause a visual problem, even with perfect eyes.

Common visual problems after brain injury

Problem	What it looks like	Brain area often involved
Hemianopia	Can’t see into half of the visual field	Occipital lobe
Visual neglect	Ignores one side even though vision is intact	Right parietal lobe
Diplopia (double vision)	Sees two images; worse when tired	Brainstem, cranial nerves
Convergence insufficiency	Eyes don’t track together; reading is hard	Brainstem
Photophobia	Oversensitivity to light; headaches in bright spaces	Various; common after TBI
Visual processing delay	Sees fine but is slow to make sense of it	Widespread
Prosopagnosia	Can’t recognise faces (rare)	Temporal lobe

What recovery looks like

Recovery depends on the type and cause of the problem:

Hemianopia - spontaneous recovery in the first months is possible; after that, compensation strategies (scanning, optical aids) become the primary approach.
Neglect - often improves with scanning training; can resolve significantly in weeks to months with consistent practice.
Double vision / convergence - prism glasses, patching, and eye exercises often help; many cases resolve.
Processing speed - typically improves with rest, fatigue management, and gradual return to visually demanding tasks.

Getting assessed

A standard optometrist appointment may not pick up neurological vision problems. Ask your doctor for referral to:

A neuro-ophthalmologist for field defects and double vision.
An orthoptist for eye movement and tracking problems.
An occupational therapist trained in perceptual rehabilitation for neglect and visual processing issues.

Everyday strategies

Reading: use a ruler or card under each line; increase text size; reduce page contrast if white backgrounds are harsh.
Glare: wear tinted glasses; use matte surfaces; use warmer indoor lighting.
Fatigue: visual processing is effortful after brain injury; rest before demanding tasks (driving, screens, busy environments).
Environment: reduce visual clutter; use bold contrast (coloured edges on steps, contrasting crockery).