Vision is said to be blurry if objects appear hazy or cloudy while looking at them. This could occur while looking at distant and/or near objects, in one or both eyes, under bright or dim lighting and could be transient or continuous.
Causes of Blurry Vision
Common causes of blurry fall into three categories:
- Refractive errors and presbyopia
- Other eye conditions and diseases
- Medical conditions with eye symptoms
Refractive Errors and Presbyopia
Refractive errors ( myopia, hyperopia and astigmatism) and presbyopia are the most common causes of blurry vision.
With these conditions, blurry vision occurs because light entering the eyes fails to focus sharply on the retina.
In myopia (nearsightedness), the eyeball is too long or the cornea is too curved such that light that enters it focuses in front of the retina. This results in blurry far vision.
In hyperopia (far-sightedness), the eyeball is too short or the cornea is too flat such that light that enters it focuses behind the retina and results in blurry near vision.
In astigmatism, the curvature of the cornea is irregular. Light entering the eye under this condition fails to come to a single focus on the retina resulting in blurry vision at both near and far distances with images looking distorted.
In presbyopia, age-related changes in the lens gradually limit its ability to focus light on the retina during near work. This causes blurry vision while performing near tasks such as reading small prints or threading a needle.
Other Eye Conditions and Diseases
Eye diseases and other eye health conditions that can cause blurry vision include:
Amblyopia: In Amblyopia, vision is reduced and blurry in one or both eyes because of poor stimulation of the eyes in the early years of life.
Cataract: Blurry vision in cataract is caused by the clouding of the lens.
Glaucoma: Glaucoma is a group of eye conditions that gradually damage the optic nerve resulting in progressive loss of vision. people who have the condition often experience blurry vision when there is a build of fluids in the eye or as vision loss progresses.
Medical Conditions with Eye Symptoms
Blurry vision can also be a visual symptom of other health problems like;
Diabetes: Diabetes is a group of diseases that result in high levels of sugar circulating in the blood. It causes blurred vision when the blood sugar level is so high that the lens swells up and its focusing ability gets affected.
Hypertension: This is a prolonged increase in blood pressure beyond normal levels. It can damage the blood vessels in the retina and cause fluid to build up in the eye. It can cause blurred vision and also lead to permanent vision loss if the condition is not brought under control.
Multiple Sclerosis: This is an auto-immune disease that damages the central nervous system and interferes with communication between the brain and other parts of the body. It causes blurring of vision if the optic nerves are affected.
Pre-eclampsia: A condition in pregnant women characterized by high blood pressure, water retention, and protein in the urine. Severe cases can cause blurry vision due to a build-up of fluids in the eyes.
What to do when you have blurry vision
If you experience mild and transient blurring of vision once in a while, try blinking and resting your eyes.
If blurry vision is mild and persistent, you should plan to see the eye doctor as soon as possible for proper diagnosis and treatment.
If blurry vision appears suddenly or worsens rapidly, consult the eye doctor immediately as a sudden change in vision could be a symptom of a serious eye or other health condition.