What causes sudden blurry vision?

Causes of sudden blurred vision include retinal detachment, retinal vein occlusion and vitreous hemorrhage, as stated by the Eye Institute. Some cases of blurred vision occur after an injury to the eye, and every instance requires immediate medical attention.

Retinal detachment is a medical emergency that occurs when the retina is removed from the oxygen-supplying blood vessels, and permanent vision loss can occur if the condition goes untreated, according to Mayo Clinic. Although the condition is painless, the individual may experience a sudden curtain or shadow-like layer over the eye's visual field, the sudden appearance of floaters or the appearance of light flashes. Retinal vein occlusion occurs when a small blood clot prevents blood flow to the retina and is more common in people with diabetes, as stated by Cleveland Clinic. Blurring or vision loss may progress over the course of several hours or days, but some patients experience vision loss almost instantly.

Vitreous hemorrhage refers to the leaking of blood into the liquid vitreous of the eye and occurs in seven out of every 100,000 people, as confirmed by EyeNet Magazine. Symptoms may include floaters, haze, shadows or a red tint in vision, and symptoms may be worse in the morning. The condition is easily diagnosed with a visual examination.