There are a variety of causes of a sudden decrease in vision which may affect one or both eyes and may develop within a few hours or days. Anyone who experiences a sudden loss of vision should consult an ophthalmologist urgently.

WHAT CAUSES VISION LOSS?

The lens of the eye focuses light onto the retina. The retina transmits images to the brain to generate sight. Anything that blocks the passage of light from the environment onto the retina or disrupts the transmission of impulses between the retina and the brain can cause a decrease in vision.

Vision loss can be the result of clouding of the transparent media (including the cornea, lens and vitreous) or abnormalities of the retina or the optic nerve pathways.

In rare cases, a decrease in vision may be caused by a stroke or transient ischemic attack (TIA), acute glaucoma or eye infection.

It is essential to contact your ophthalmologist for an urgent appointment if you do notice a sudden decrease in vision.

HOW IS VISION LOSS DIAGNOSED AND TREATED?

Your ophthalmologist will be able to evaluate and diagnose the cause for the decreased vision using an instrument called a "slit lamp", a binocular microscope which illuminates the eye for detailed examination.