What is blurred vision?
Blurred vision or blurry vision is a loss of sharp vision. You may experience sudden or gradual blurry vision in one or both eyes.
Blurred vision can be a symptom of a variety of mild to serious diseases, disorders or conditions. Blurred vision can result from minor problems, such as nearsightedness or wearing the wrong eyeglasses. Blurred vision can also be a normal sign of aging. However, blurred vision can also result from infection, inflammation, trauma, malignancy, and other abnormal processes; therefore, you should discuss any vision changes with a medical professional.
Certain types of vision changes can indicate a medical emergency, which can lead to loss of sight, such as with glaucoma, an eye injury, or retinal detachment, or loss of life, such as in the case of stroke or bleeding in the brain if you do not seek emergency care. Even temporary blurred vision should not be ignored because it can result from serious conditions, such as stroke, transient ischemic attack (TIA), hypertension, or epilepsy.
Depending on the cause, blurred vision can begin suddenly and disappear quickly, such as when your eyes are refocusing on a far object after reading, or after sun overexposure. Blurred vision can also occur in sudden, severe episodes, such as blurred vision from a detached retina or head trauma. Blurred vision that is slow to develop and accompanied by additional symptoms, such as halos around lights, may be a sign of cataracts.
Any change in vision should always be evaluated by a medical professional. Blurred vision can be a symptom of a serious disorder, such as encephalitis, a brain tumor, or retinal detachment. If you experience blurred vision with a sudden, severe headache, stiff neck, nausea or vomiting, seek immediate medical care (call 911).
What other symptoms might occur with blurred vision?
Blurred vision may be accompanied by other symptoms, which vary depending on the underlying disease, disorder or condition.
You may experience problems with the eye itself, or you may have symptoms that affect other body systems, such as the neuromuscular and immune systems. For example, blurred vision due to an autoimmune disorder may be accompanied by joint pain or stiffness. Blurred vision due to a refractive error, such as nearsightedness, may be accompanied by a minor headache.
Vision-related symptoms that may occur along with blurred vision
Blurred vision may occur with other symptoms affecting the eyes including:
Bleeding from the eye
Discharge from the eye
Increased sensitivity to light
Increased tear production
Loss of central or side (peripheral) vision
Poor close-up or near vision
Poor nighttime vision
Seeing floating objects or spots
Other symptoms that may occur along with blurred vision
Blurred vision may occur with symptoms related to other body systems including:
Butterfly-shaped rash over bridge of nose and cheeks
Serious symptoms that might indicate a life-threatening condition
In some cases, blurred vision may occur with other symptoms that might indicate a serious or life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms:
Blurred vision after head trauma
Change in level of consciousness or alertness, such as passing out or unresponsiveness
Difficulty understanding speech
Garbled or slurred speech or inability to speak
High fever (higher than 101 degrees Fahrenheit)
Numbness or paralysis on one side of the body
Seeing halos around lights or having blind spots or distorted vision
Sudden change in vision, loss of vision, or eye pain
Weakness (loss of strength)
What causes blurred vision?
Blurred vision is caused by a variety of mild to serious diseases, disorders and conditions. While many cases of blurred vision are due to problems with the eyes, blurred vision can also be due to neurological and autoimmune disorders. Many of the causes are very serious medical conditions.
Optical or eye-related causes of blurred vision
Blurred vision can be caused by several kinds of common vision problems:
Astigmatism (when light rays do not focus clearly at one point on the retina due to the unequal curvature of the surface of the eye)
Farsightedness (hyperopia, when eyes focus better on distant objects than near objects)
Nearsightedness (myopia, when eyes focus better on near objects than distant objects)
Presbyopia (a normal, gradual loss of your eyes’ ability to focus on near objects due to aging)
Wrong prescription for eyeglasses or contact lenses
Diseases and conditions of the eye can lead to blurred vision
Several different diseases, disorders and conditions that cause blurry vision include:
Conjunctivitis (inflammation of the eye surface)
Eye inflammation or infection
Glaucoma (where fluid pressure builds up in the eye, including narrow angle glaucoma and acute angle glaucoma)
Macular degeneration (condition that causes blurring of the central vision)
Optic neuritis (inflammation of the optic nerve)
Retinal detachment (detachment of the light-sensing layer inside your eye from the blood vessels that provide it oxygen and nutrients)
Retinal vessel occlusion (blockage of the blood vessels of the eye)
Retinoblastoma (cancer of the retina)
Retinopathy and diabetic lens osmosis (complications of diabetes)
Uveitis and iritis (inflammation of the uvea)
Autoimmune causes of blurred vision
Some autoimmune diseases result in blurred vision including:
Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
Other causes of blurred vision
Various other diseases, disorders and conditions that cause blurred vision include:
Amphetamines and other illicit drugs
Sarcoidosis (inflammatory disease most commonly affecting the lungs, skin and eyes)
Temporal arteritis (inflammation of blood vessels in the head)
Transient ischemic attack (also known as TIA, temporary stroke-like symptoms that may be a warning sign of an impending stroke)
Life-threatening causes of blurred vision
In some cases, blurred vision may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:
Atherosclerotic emboli (plaque that travels to the brain and can cause a stroke)
Brain hemorrhage (bleeding in the brain)
Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)
What are the potential complications of blurred vision?
Blurred vision complications depend on the underlying disease, disorder or condition. Complications of untreated or poorly controlled blurred vision can be serious and even life threatening. A delay in treating a vision problem can lead to loss of sight, such as with glaucoma, an eye injury, or retinal detachment, or loss of life, such as with stroke or brain hemorrhage. Even temporary blurry vision can result from serious conditions, such as stroke, transient ischemic attack (TIA), hypertension, epilepsy or migraine. Over time, blurred vision and the underlying cause of blurred vision can lead to serious complications including:
Loss of sight (blindness)
Loss of the eye and orbit (bony part surrounding the eye globe)