What Causes Double Vision in One Eye?

There are various visual disturbances that can affect the eye. This includes blurry vision, partial sight loss, seeing objects that are not really there and double vision. These symptoms can happen in both eyes or just one. The types of symptoms present will help a physician to correctly diagnose any underlying disease that is occurring. In the case of double vision in one eye, once the cause is known then the correct treatment plan can be implemented.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Cataracts are a common eye problem in the elderly. They occur when proteins that are naturally found in the eye start to clump together, which clouds over the lens of the eye, states the National Eye Institute 1. In the early stages when the cataract is small, it may distort vision to the point that multiple images (double vision) occurs in the affected eye. As the cataract grows in size, double vision may change to general blurred vision.


Keratoconus is a condition in which the cornea or clear round shaped portion of the eye, becomes abnormally thin. This can cause the eye to bulge, which will distort vision in the affected eye. The exact cause of this condition remains unknown but constantly rubbing the eyes may contribute to its development. The Mayo Clinic claims that keratoconus can cause a wide variety of visual disturbances including sensitivity to light, cloudy vision and double vision in one eye 2.

Weak Eye Muscles

If the muscles that control eye movement become weak or damaged then the eye will not be able to move in order to interpret images properly. This can lead to double vision in just one eye. According to an article in Clinical Methods, weak muscles may move the eye incorrectly or not at all, causing an inability to focus 3.

Astigmatism and Dry Eye

Many common conditions that affect the shape of the eye or the ability of the eye to function properly can contribute to double vision in one eye. The John's Hopkins website states that astigmatism and dry eye are two conditions that can contribute to seeing double. Dry eye occurs when the eye are not able to produce enough of their own tears. Astigmatism is diagnosed when the cornea is abnormally curved. In addition if there is damage to the retina or it becomes detached double vision may occur.