• Reference Number: HEY1152/2020
• Departments: Ophthalmology Department, Orthoptic
• Last Updated: 19 December 2023

Introduction

This leaflet has been produced to give you general information. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is monocular vision?

Monocular vision is where an individual is reliant on only one eye for their vision. This may be due to the loss of vision in one eye due to a disease process, or as a result of a need to cover (occlude) one eye using a patch or similar to stop double vision (diplopia). Whether it is short or long term, gradual or sudden, it is normal for it to take time to adjust.

Why do I need to adapt?

Having to rely on the sight from one eye will take time to adjust to both emotionally and practically. This will be the case even if the loss of sight is not complete, as the poor sight from the affected eye may ‘interfere’ with the vision of the good eye. You will have to learn to use your vision in a different way and at times this may not be as automatic as before. Your visual system will have to adjust to this new level of sight and you will have to learn to trust what you are seeing.

The two measurable differences in your vision will be a loss of the peripheral vision to the affected side of approximately 30%, and a loss of depth perception (3D vision). Peripheral vision is important in being able to navigate through your environment; the loss of some of this will impact on your ability to do this as well as you used to. The picture below shows how the loss of your peripheral vision may affect what you see. The area of loss is shown to greyed out on the right.

Loss of depth perception (3D vision) will be an issue for items within three metres. Depth perception is essential in judging distance, for example judging the height of steps or kerbs, and correctly coordinating when pouring a liquid into a cup.

You may also find you are unable to work in the same way as before due to becoming more easily fatigued as your brain tries to adjust to making the best use of your remaining vision. Being reliant on one eye will not damage the good eye, though you may find it helpful to take regular breaks to prevent fatigue.

The change to your vision and working through the adaptation phase will naturally cause frustration, however be assured you will adjust with time. The brain is very adaptable, and in the same way you are able to learn new skills as you grow older, the brain will adjust to this new way of seeing. How long this will take varies from person to person dependent on the level of change to your vision and your visual needs. However, once someone has adjusted to monocular vision, they find that they are able to read, watch television and perform many day to day activities without any problems.

Practical tips to help you adjust

• When reaching for an object open your hand wide and move slowly towards it until you feel the object.
• When pouring liquid, gently rest the lip of the container on the rim of the cup or glass to ensure you are in the correct position before you start to pour.
• It can be difficult when using steps, take your time and move cautiously. Always use a banister or handrail if available and feel ahead with your foot for the next step.
• When crossing the road try and always use designated crossings if available. Take extra care to stop, to enable you to judge the depth of the kerb and to judge the distance of vehicles before crossing.
• Make others aware of what is best for you in order to make the best use of your sight.
• You may find it useful to turn your head to the affected side. This will enable you to see more on the affected side and centralise your vision – with time this will become more natural.
• In crowded areas, you may find it is helpful having whoever you are with to be on your affected side. This will prevent you from bumping into obstacles on that side.

How do I prepare for the loss of sight in one eye?

In cases of gradual loss of sight in one eye it is possible to prepare by informing friends and family so they are aware and are then able to support you with making adjustments to your daily life. There are also many useful resources online such as the Royal National Institute for the Blind (RNIB https://www.rnib.org.uk/) website which has useful information, practical tips, links for sources of support, as well as an online shop with lots of useful items available to buy.

Will I be able to drive?

In regards to driving, if you have lost vision in one eye for a short period of time due to wearing an eye patch or having dilating drops it is advised not to drive during this time.

If your vision loss is permanent you may still be able to legally drive if your other eye has vision good enough to meet the Driver and Vehicle Licensing Agency (DVLA) standards and you have adapted to sight loss in one eye. If you have lost the vision suddenly it takes time to adjust so driving is not advised for the first three months whilst you get used to seeing with one eye.

You must first check with the DVLA and your insurance company before driving again.

You will need to move your head more to compensate for the loss of vision on the affected side.

Looking after your better seeing eye

It is important that you look after the sight in your good eye by attending regular eye tests with your local Optometrist (Optician). It is also important to protect the eye with use of protective eye wear/goggles for activities such as DIY or gardening as well as sports, particularly contact and/or ball sports.

Will I be able to register as partially sighted?

No, though this may seem confusing. There are strict criteria that govern who are able to be registered as Sight Impaired / Partially Sighted. This is because both eyes need to be affected by loss of vision in order to meet the criteria for certification. The criteria for certification and registration are set nationally by the Department of Health and applied at the discretion of a Consultant Ophthalmologist (Eye doctor).

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Orthoptic Department on telephone: (01482) 816605.