What is blurry diplopia

Seeing double images - causes and therapy

Seeing twice - diplopia
Normally, the brain combines the impressions of the right and left eyes into one complete picture. However, if you suffer from diplopia, you see things twice - either in one eye or in both eyes at the same time.

We differentiate between monocular and binocular double images. Monocular double images arise when the eye refracts incident light rays differently in the lens and cornea. The same object creates two different images on the retina and in the brain.

Binocular double images are more common. This creates a different image in each eye. Some of those affected see images shifted to the side, with others the image tilts, others perceive their surroundings as blurred, but see two images that overlap.

Patients can no longer judge distances correctly, so they have problems grasping things and walking. They find physical work difficult, they have poor conditioning of their movements, and they complain of exhaustion from exerting themselves excessively to focus on everyday objects.

The cause of this can be harmless, for example if an eye muscle is strained. Sometimes, however, there is a serious illness behind it - up to and including a brain tumor.

What happens with double vision?

There are many causes of diplopia.

1) In the case of eye muscle paralysis, the double vision occurs because the person concerned cannot move the eye muscles appropriately.

These muscles include the six eye muscles and the eyelid elevator muscle. Three nerve nerves transmit information to these muscles.

Such paralysis occurs when the cranial nerves are damaged. This damage is often caused by a basic disease, for example a tumor or impaired blood circulation.

The paralyzed muscles can no longer process information from the brain.

2) eye movement disorders

Movement disorders in the eyes result from injuries to the eye socket. If the eye cannot barely move in the cave, we see double.

3) Congenital malfunctions in the eye muscles can lead to changes in the structure of the muscles. Then we see double images, they appear shifted to the side or tilted.

Orbital diseases

Double vision is also caused by injuries to the walls of the eye socket - mostly through violence. A blow to the eye that fractures the walls of the cavity can pinch the eyecups. Now the eyeball can hardly move. If a nerve is also damaged, the eye muscle also relaxes. A bone fracture must be operated on.

The eye sockets can also become inflamed, and an infection of the paranasal sinuses often spreads to the eye. The movement of the eyes is then restricted in all directions, regardless of where the person concerned looks, everywhere they perceive images twice. Antibiotics help effectively here.

It is easy to confuse orbital inflammation with non-infectious diseases of the eye muscles or connective tissue, which also trigger the same symptoms. No antibiotics help here, but cortisone - over a longer period of time.

Diseases of the cranial nerves

We recognize paralyzed cranial nerves, among other things, by the fact that those affected cross-eyed.

The fourth cranial nerve is connected to the upper muscle of the eye. When no more information reaches the muscle, the eye no longer sinks down and can no longer roll inward. The double images are vertically offset and tilted. The images intensify when the head tilts to the affected side or the eyes are directed downwards.

The sixth cranial nerve sends the impulses to the external eye muscle. If it fails, the eye turns inward.

The third cranial nerve is responsible for the other four eye muscles. If it fails, the eye slides outwards. Looking up and down is only possible to a limited extent.

This nerve paralysis is usually caused by a disturbed blood circulation, and this is usually associated with diabetes mellitus. Heavy smoking and high blood pressure can also cause this disorder.

Double vision in paralysis of the fourth cranial nerve usually arises from an injury, i.e. from a traumatic brain injury. As a rule, those affected do not squint and see tilted double images when they look down.

When the sixth cranial nerve is paralyzed, the volume of the brain usually increases, be it due to a tumor or internal bleeding.

After treating the causal disease, the doctor waits a year so that nerves and muscles can regenerate. Squinting as a result of paralysis can be treated with an operation that will now follow.

Until this operation finally eliminates the deformity, those affected wear glasses with erecting prisms.

People who suffer from paralysis of the cranial nerves suffer from dizziness, their sense of space is impaired, and they try to compensate for the distorted view by tilting their head to one side.

Seeing twice with just one eye

Keratoconus is a rare disease of the cornea. Around 40,000 people in Germany suffer from this. The affected cornea bulges and thins out.

The disease is most common in men in their 20s. The refractive power of the eye changes again and again and so their poor eyesight fluctuates. You see “shadows” on letters and you see twice - but only in one eye.

The cause is unknown. Ophthalmologists recognize keratoconus with a corneal topography. They measure the thickness of the cornea and use a slit lamp microscope to examine how the cornea changes.

Double vision caused by alcohol

Very drunk people see twice. This has little to do with any other visual impairment. Alcohol does not affect whether someone is nearsighted or farsighted.

If we have drunk too much, on the other hand, the interaction between the brain and the eye is disturbed. The nerve impulses no longer reach the eye system, and where a three-dimensional image is created from the impressions of both eyes in a sober state, two images suddenly dance around. Both eyes have to look in exactly the same direction in order to merge their images. This is no longer possible after heavy alcohol consumption.


Double vision can be treated in the same way as the diseases that underlie it.

A prism film on the glasses or a special lens with prism layers restore the overall picture. Often the affected eye has to be covered, but this is only a solution for short-term eye disorders. (Dr. Utz Anhalt)

Author and source information

This text complies with the requirements of specialist medical literature, medical guidelines and current studies and has been checked by medical professionals.

Dr. phil. Utz Anhalt, Barbara Schindewolf-Lensch
  • Herbert Kaufmann; Wilfried de Decker: Strabismus: 72 tables, Georg Thieme Verlag, 2004
  • Professional Association of Ophthalmologists in Germany (BVA): cms.augeninfo.de (accessed: 08/20/2019), Seeing twice with one eye
  • Professional association of Orthoptistinnen Deutschlands e.V .: www.orthoptik.de (accessed: August 18, 2019), treatment options for double vision (diplopia) in acquired eye muscle paralysis (paresis)
  • DUPLICON company: www.sehtestbilder.de (accessed: August 18, 2019), double seeing under the influence of alcohol
  • Deutscher Ärzteverlag GmbH: www.aerzteblatt.de (accessed: August 17, 2019), side note: alcohol and double vision
  • Annelie Burk; Reinhard Burk: Checklist ophthalmology, Georg Thieme Verlag, 2014
  • Hedwig J. Kaiser: "Diplopia: From Symptom to Diagnosis", in: Clinical Monthly Papers for Ophthalmology, Volume 214 Issue 5, 1999, Thieme Connect
  • Klaus Miehlke: Negotiations of the German Society for Internal Medicine, Springer, 1990

Important NOTE:
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor.