Blurry vision is the loss of sharpness of eyesight, making objects appear out of focus and hazy.
The primary causes of blurred vision are refractive errors — nearsightedness, farsightedness and astigmatism — or presbyopia. But blurry vision also can be a symptom of more serious problems, including a potentially sight-threatening eye disease or neurological disorder.
Blurred vision can affect both eyes, but some people experience blurry vision in one eye only.
Cloudy vision, where objects are obscured and appear “milky,” is often mistaken for blurry vision. Cloudy vision usually is a symptom of specific conditions such as cataracts, but blurry and cloudy vision can both be symptoms of a serious eye problem.
A qualified eye doctor can measure the extent of your blurred vision and determine the cause with a comprehensive eye exam.
Sudden blurry vision that persists could be a sign of a serious health problem, and you should see a doctor immediately.
Blurry vision in one eye or both eyes may be a symptom of myopia (nearsightedness), along with squinting, eye strain and headaches. Myopia is the most common refractive error and causes objects in the distance to become blurred.
Blurred vision from hyperopia (farsightedness) is when distant objects can be seen sharply but your eyes can’t focus properly on close-up objects or doing so causes unusual eye strain and fatigue. In cases of severe farsightedness, even distant objects may appear blurred.
Blurred vision at all distances often is a symptom of astigmatism. A type of refractive error, astigmatism usually is caused by an irregularly shaped cornea.
If you’re over 40 and beginning to experience blurry vision up close — when reading a newspaper or other small print, for example — chances are this is due to the onset of presbyopia, a naturally occurring age-related condition.
Blurry vision is common during pregnancy and sometimes is accompanied by double vision (diplopia). Hormonal changes can alter the shape and thickness of your cornea, causing your vision to blur. Dry eyes also are common in pregnant women and can cause blurred vision.
While generally harmless and temporary, blurred vision, flickering light, halos or zigzag patterns are all common symptoms prior to the start of an ocular migraine or migraine headache.
Vision can be blurred by temporary spots or floaters drifting in your field of vision. Floaters typically appear when the eye’s gel-like vitreous begins to liquify with age, causing microscopic bits of tissue within the vitreous to float freely inside the eye, casting shadows on the retina.
Eye conditions and diseases
If you have sudden blurry vision in one eye and are over 60, you may have developed a macular hole in the part of the retina where fine focusing occurs. Blurry vision also may be a symptom of a detached retina, eye herpes or optic neuritis (inflammation of the optic nerve), among other causes.
Vision changes such as blurred vision or cloudy vision, as well as glares and night “halos,” may be symptoms of a cataract. If unremoved, cataracts can eventually grow so cloudy that they obstruct vision to the point of blindness. But by replacing cataracts with artificial lenses, cataract surgery is very successful in restoring lost vision.
Blurry vision or “tunnel vision” may be indicative of glaucoma. Symptoms can include a gradual or sometimes sudden narrowing of your field of vision accompanied by blurred vision at the edges of your field of view. Without intervention, vision loss will continue, and permanent blindness may result.
Age-related Macular Degeneration (AMD)
A gradual loss and blurring of vision, including distortions such as straight lines appearing wavy or broken, could be symptoms of age-related macular degeneration (AMD), a leading cause of blindness among older people
If you have diabetes, unexplained blurred vision may be due to the onset of diabetic retinopathy, a sight-threatening disease that damages the retina of the eye.
Source: All About Vision