Double vision (diplopia) - Newcastle Hospitals NHS Foundation Trust

If you have any further questions, please ask a member of the eye care team.

What is double vision?

Double vision, or diplopia, means seeing two of the object you are looking at. It may be present all of the time or may only occur when you look in certain directions or distances. It may develop suddenly or gradually.

There are two types of double vision

Monocular

Present when looking only out of the affected eye, and is generally seen as a shadow or ghosting.

Binocular

Present only when looking out of two eyes together and generally seen as two separate or overlapping images but occasionally as ghosting. The images may be side by side (horizontal), one above each other (vertical) or a combination (diagonal). Sometimes one image is tilted. The double vision goes away which ever eye is covered.

What causes double vision?

Monocular

Common causes include dry eye, cataracts, retinal problems and astigmatism (rugby ball shaped eye).

Binocular

There can be many causes:

Eye muscle or nerve problem can cause a strabismus (squint) where the eyes are out of alignment.
There are many common health conditions that can affect the nerves e.g. diabetes, high blood pressure. Smoking is known to be a risk factor
Previous eye surgery to correct a childhood squint: sometimes the eye moves from its corrected position and the brain becomes aware of a previously “ignored” eye.
Brain or head injury can disrupt the ability to join the images from each eye and see them as a single picture.
Side effect of certain medications.
Eye strain or tiredness can cause intermittent double vision if there is an underlying eye muscle weakness.

What problems can double vision cause?

Imbalance/ unsteadiness
Problems with mobility, particularly stairs
Inability to drive safely
Difficulty concentrating or reading
Neck / shoulder pain if using an unusual head position to join the double vision
Low mood.

How long will the double vision last?

This will depend on the cause and will be fully discussed with you.

Where there has been temporary nerve damage you may notice gradual improvement over a period of weeks or months. There may be full or only partial recovery.

If the double vision is of recent onset and is not improving the ophthalmologist may suggest having further tests to establish the cause. You may be referred to another hospital specialist.

Sometimes the double vision is permanent and may be very troublesome.

Can anything be done about double vision?

Monocular double vision

This will depend on the cause of the double vision and you should discuss this with the ophthalmologist who is treating your eye condition.

Sometimes covering the affected eye with a patch or blurring the vision in one eye will be recommended.

Binocular double vision

It is important to wait several months to monitor any changes in the double vision. Some possible ways to manage double vision in the short or long term are:

Short term

Patching one eye

There are different types of patch available: A “pirate” patch with an elastic strap; a fabric patch/ frosted tape applied to one spectacle lens; a sticky patch applied directly to the face. Covering one eye will not make it weaker, strain the other eye or stop the double vision improving.

Fresnel prism

This is a plastic sheet of tiny prisms that can be applied to one spectacle lens. The prism “bends” the light so that the double images are either joined; enabling the eyes to work together as a pair, or separated so that one image can be more easily ignored. The double vision will only be controlled when the glasses with the prism on are worn and often only when looking straight ahead. Fresnel prisms cause a slight blurring of the vision. They may not be useful if the double images are extremely far apart in which case a patch may be recommended. For more information, see the leaflet “Fresnel prisms”.

Compensatory head position

You may notice that double vision improves when you look in a certain direction. The orthoptist may be able to advise you to adjust your head position in order to gain temporary relief.

Exercises

These can be useful when double vision is caused by an underlying muscle weakness which affects the ability of the eyes to pull inwards (converge) when reading. Otherwise exercises are not helpful.

Long term

Botulinum toxin (Botox)

can be injected into an eye muscle to temporarily weaken it and reduce the misalignment. The effect wears off after approximately three months but the injection can be repeated if necessary. The ophthalmologist will advise if this treatment is suitable for you.

Surgery

it may be possible to perform surgery on the eye muscles to straighten the eyes. The ophthalmologist will advise if this is recommended for you.

Permanent prisms

These are only used if double vision persists after a recovery period has been allowed and a Fresnel prism has been helpful. The prism is built into a pair of glasses and has the advantage that there is no blurring effect. You may need to have separate reading and distance glasses rather than bifocals/ varifocals. If the required prism is very strong then a Fresnel prism may needed in addition.

Optical penalisation

If you wear glasses then the optometrist (optician) may be able to change the strength of one of the lenses in one eye in order to blur the vision. This may enable you to more easily ignore the double image. It is generally only used when double vision is permanent.

Other options

if your diplopia is extremely troublesome then other options would be discussed on a case by case basis.

Can I drive with double vision?

Driving and Vehicle Licensing Agency (DVLA) requirements

If your double vision has started recently then you must inform the DVLA and stop driving until your ophthalmologist confirms:

1. Your double vision is controlled with one of the treatments above

2. You are safe to drive.

Using one eye only is not acceptable for group 2 drivers i.e. bus and lorry.

Sometimes you can drive with stable (unchanged over at least six months), uncorrected, long-term double vision if your ophthalmologist confirms to the DVLA that you have adapted to this. This is not acceptable for group 2 drivers.

Who can manage the double vision?

Ophthalmologist

A doctor who is specialised in diagnosing and treating defects, injuries and diseases of the eye. Some specialise in eye movement problems and double vision. They will advise on overall management of your eye condition.

Orthoptist

An allied health professional (AHP) specialised in diagnosis and treatment of strabismus (squint), binocular vision and eye movement problems. They will monitor any changes and advise on prisms or patching to help with double vision.

Optometrist (optician)

A specialist trained to detect defects in vision. They will advise on the use of glasses, contact lenses and permanent prisms.

For further information

Contact details

Appointments Office

To change or cancel an appointment call 0191 282 4444

Monday to Friday, 9am to 5pm (excluding Bank Holidays)

Orthoptic department

To speak to an orthoptist about treatment: 0191 282 4434

Monday to Friday 9am to 5pm (excluding Bank Holidays)

PALS (Patient Advice and Liaison Service) for help, advice and information about NHS services. You can contact them on Freephone 0800 032 02 02, e-mail the North of the Tyne PALS department or text to 07815500015.

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