When vision in one eye becomes unclear or hazy, it is known as unilateral blurry vision. Many underlying causes are treatable, often leading to a restoration of clear sight.
Common Reasons for Unilateral Blurry Vision
Refractive errors, such as astigmatism, myopia (nearsightedness), or hyperopia (farsightedness), can sometimes affect one eye more than the other, causing uneven blurriness. These conditions occur when the eye’s shape prevents light from focusing properly on the retina.
Dry eye syndrome, caused by insufficient tear production or poor tear quality, leads to fluctuating blurriness, discomfort, and irritation. Prolonged digital screen use can also cause temporary blurry vision due to eye strain. Mild eye injuries or foreign objects, like dust, can irritate the eye and cause transient blurriness.
Ocular or retinal migraines can cause temporary visual disturbances, including blurry vision or temporary blindness in one eye, often preceding a headache. Conjunctivitis (pink eye), an inflammation of the conjunctiva, can also lead to blurry vision due to discharge or irritation.
Urgent Conditions Affecting One Eye
Some causes of blurry vision in one eye signal serious conditions that require immediate medical attention. Retinal detachment is an emergency where the light-sensitive tissue at the back of the eye pulls away from its supporting layers. Symptoms often include a sudden increase in flashes of light, new floaters, or the sensation of a curtain or shadow moving across the field of vision.
Optic neuritis involves inflammation of the optic nerve, causing sudden vision loss or blurriness, often with pain, especially with eye movement. Acute angle-closure glaucoma is an ocular emergency characterized by a rapid increase in pressure inside the eye. This can lead to sudden, severe eye pain, redness, nausea, and the perception of halos around lights, potentially causing permanent vision loss if untreated.
Sudden, painless vision loss in one eye can be a symptom of a stroke or transient ischemic attack (TIA), particularly if accompanied by other neurological signs like facial drooping, arm weakness, or speech difficulty. Wet age-related macular degeneration (AMD) involves abnormal blood vessel growth under the retina, which can leak fluid or blood, leading to sudden distortion or loss of central vision. Individuals with diabetes may experience sudden vision changes, floaters, or blur due to advanced diabetic retinopathy, where high blood sugar damages retinal blood vessels.
Severe eye infections, such as keratitis or endophthalmitis, can also cause significant pain, redness, and rapid vision loss. These infections are more likely in individuals who wear contact lenses improperly or have recently undergone eye surgery.
Knowing When to Get Professional Help
Knowing when to seek professional help for blurry vision in one eye is important for protecting eye health. Immediate emergency medical attention is necessary for:
- Sudden, severe, or painless vision loss.
- Vision loss accompanied by headache, weakness, or numbness.
- Sudden onset of flashes, a significant increase in floaters, or the sensation of a “curtain” over vision.
- Severe eye pain combined with blurriness.
- Any vision loss following head or eye trauma.
These symptoms could indicate conditions like retinal detachment, acute angle-closure glaucoma, or a stroke. Call emergency services or go to the nearest emergency room in these situations.
Urgent care from an eye doctor within 24 hours is advisable for sudden blurriness without severe pain or other neurological symptoms. This also applies to blurriness accompanied by increasing redness or discharge, or blurriness after any eye injury, even if seemingly mild. Conditions like severe eye infections or corneal abrasions can progress rapidly.
For gradual onset of blurriness, vision that comes and goes, or blurriness suspected from eye strain or dry eyes, schedule a routine appointment with an eye doctor. A comprehensive eye examination can identify refractive changes or other underlying issues.
How Eye Specialists Diagnose and Treat
When a person experiences blurry vision in one eye, eye specialists employ a range of diagnostic tests to pinpoint the underlying cause. A comprehensive eye exam typically begins with measuring visual acuity to assess the sharpness of vision. The doctor then examines the eye’s external structures, internal components, and the back of the eye, including the retina and optic nerve, often using a slit lamp microscope.
Specialized tests may include measuring intraocular pressure to check for glaucoma, and a dilated eye exam to get a clearer view of the retina. Imaging techniques like Optical Coherence Tomography (OCT) can provide detailed cross-sectional images of the retina, while fluorescein angiography might be used to visualize blood vessels in the eye. Visual field testing helps detect blind spots or areas of diminished vision that might indicate optic nerve damage or other issues.
Treatment approaches for unilateral blurry vision vary significantly depending on the diagnosis. Refractive errors are commonly corrected with prescription eyeglasses or contact lenses. Eye drops are often prescribed for conditions such as dry eye, glaucoma to lower eye pressure, or to treat bacterial or viral eye infections.
For inflammatory conditions or certain retinal diseases like wet AMD, medications may be administered orally or through injections into the eye. Surgical procedures are sometimes necessary, such as cataract removal to replace a cloudy lens, or laser treatments to address conditions like diabetic retinopathy or certain types of glaucoma. The specific treatment plan is tailored to the individual’s condition, aiming to restore or preserve vision.
General Eye Care and Prevention
Maintaining good eye health can help prevent some causes of blurry vision and support overall visual well-being. Regular comprehensive eye exams are important for detecting potential issues early, even before symptoms appear. For adults, a baseline eye examination around age 40 can be beneficial, with subsequent check-ups recommended every one to two years, or more frequently if there are risk factors for eye disease.
Protecting eyes from harmful ultraviolet (UV) radiation by wearing sunglasses that block 99-100% of both UVA and UVB rays is advised, even on cloudy days. Managing underlying health conditions like diabetes and high blood pressure is also important, as these can significantly impact eye health and increase the risk of conditions like diabetic retinopathy or glaucoma.
A diet rich in fruits, vegetables, and omega-3 fatty acids supports eye health. For individuals who spend extended periods on digital devices, following the 20-20-20 rule can help reduce eye strain: every 20 minutes, look at an object 20 feet away for 20 seconds. Proper hygiene for contact lens wearers, including thorough hand washing and correct lens cleaning and storage, minimizes the risk of eye infections.