What is sight in one eye?
In short
- Losing the sight in one eye, suddenly or over time. Depth, the view on that side and tiredness are the early problems. The brain adapts, and most people can still drive and work.
- Misjudging steps, kerbs and distances, and knocking things when reaching.
- The cause of the sight loss is treated by the eye team.
Also called: Monocular vision
- Part of the eye
- Monocular vision
- Group
- Retina & sight loss
- Vision functions involved
- Visual field, Alignment and depth
- Main source
- RNIB
Losing the sight in one eye changes how you see even when the other eye is healthy. The two eyes normally work as a pair to give three-dimensional vision, so at first depth is hard to judge: the height of a step, or pouring into a cup. The field of vision on the affected side is smaller, so people and objects on that side can be missed in unfamiliar or crowded places. If some sight remains in the affected eye it can interfere with the good eye, and the eyes tire quickly. The brain is adaptable: with time the good eye takes over and most tasks become easier.
Ophthalmologist
A medical doctor who specialises in eye conditions and their treatment. Glossary entry
Orthoptist
A professional who assesses eye movements and how the two eyes work together. Glossary entry
Sight impaired
The two levels of registration in the UK, previously called partially sighted and blind. Glossary entry
Ophthalmologist
A hospital doctor who specialises in eyes. Glossary entry
Orthoptist
A professional who assesses eye movements, squint and how the eyes work together. Glossary entry
How sight in one eye can affect day-to-day life
You may recognise some of these situations, or none of them. The point is to find help with the things you want to do.
Pouring a cup of tea
The spout and the cup seem to be in the same place.
Rest the spout on the rim, or use a liquid level indicator. It gets easier.
Walking in a crowd
People appear from the affected side without warning.
Walk with the affected side to the wall or to a companion, and turn your head often.
Changes you may notice
- Misjudging steps, kerbs and distances, and knocking things when reaching.
- Not noticing people or objects on the affected side, and eyes which tire after little effort.
Everyone is different. Symptoms on their own cannot identify a condition.
What to do about a new or sudden changeAssessment and care
The cause of the sight loss is treated by the eye team. For the remaining eye, regular sight tests matter more than ever, and any new symptom in the good eye needs prompt attention. Some people qualify for registration as sight impaired depending on the sight in the good eye, which an ophthalmologist decides. An orthoptist or low-vision service can help with adjustment and with any residual vision in the affected eye.
How vision is affected
These topics explain the parts of vision involved. They do not predict your sight, diagnose anything or show the condition itself.
Visual field
Finding a face and noticing the edge of a step make different demands on sight. One uses the centre of your view. The other uses the edges.
Open the visual field labAlignment and depth
Your brain combines the view from each eye with perspective, size and movement. Judging depth uses several clues at once.
Open the alignment and depth labEveryday support
Turn your head to check the affected side, especially when crossing roads and in crowds. Use handrails and take more time on stairs. Position cups and jugs so you can see the rim. Protect the good eye: safety glasses for DIY, sport and gardening, and sunglasses outdoors. Give yourself time to adjust emotionally as well as practically, and ask the ECLO about support.
Driving: you must tell DVLA about an eye condition which affects both eyes, or your only seeing eye. Driving and your eyesight
Common questions
Can I still drive with sight in one eye?
Often, yes, if the remaining eye meets the driving standard: reading a number plate at 20 metres, 6/12 acuity and an adequate field. You must tell DVLA about any condition affecting your remaining eye. The driving guide has the detail.
Will using my good eye all the time damage it?
No. Reading or watching television with one eye does not harm it, though the eye may tire sooner. Take breaks.
How long does it take to adjust?
It varies and is very individual. Sudden loss takes longer to adapt to than gradual loss. Depth judgement improves as the brain learns to use other clues such as size, shadow and texture.
A question to take to your appointment
What does this mean for driving, work and the health of my other eye, and who can help me adjust?Prepare your appointment checklist
Sources and review status
- Written by
- The Omnirx.io team, from the sources above
- Sources checked
- Page updated
- Next review due
- Clinical review
- Not yet. No clinician has endorsed this page.
- Reading level
- About 17 words a sentence, 269 words of guidance
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Cite this page
Glanced (2026) Sight in one eye: what the name means, care and support. Omnirx.io team for Medstack Ltd. Available at: https://www.glanced.co.uk/condition/sight-in-one-eye/ (Accessed: ). Source checked 4 October 2026.
Educational information. Follow the advice of your own eye-care team.