Overview

Blurred vision in one eye is a common but potentially concerning symptom that can range from mild and temporary to severe and vision-threatening. It refers to the partial or complete loss of sharpness or clarity in one eye, making it difficult to see fine details. While it may be caused by simple issues like eye strain or dry eyes, it can also indicate more serious underlying health problems such as retinal disorders, nerve damage, or stroke. Early evaluation is crucial to identify the cause and initiate appropriate treatment to prevent permanent vision loss.

Causes

There are numerous causes of blurred vision in one eye, which can be grouped into several categories:

• Refractive errors: Nearsightedness (myopia), farsightedness (hyperopia), or astigmatism can cause blurry vision, especially if only one eye is affected.
• Dry eye syndrome: Insufficient tear production can cause intermittent or constant blurriness, often relieved by blinking.
• Migraines: Ocular or visual migraines may cause temporary blurred vision, sometimes with a shimmering or zig-zag pattern.
• Eye infections: Conjunctivitis, keratitis, or corneal ulcers can cause blurred vision due to inflammation or infection.
• Retinal problems: Conditions like retinal detachment, macular degeneration, or macular holes can cause acute or progressive blurring in one eye.
• Optic neuritis: Inflammation of the optic nerve, often linked to multiple sclerosis, can cause sudden blurry vision and eye pain.
• Vitreous issues: Posterior vitreous detachment or vitreous floaters may cause visual disturbances including blurred vision.
• Stroke or transient ischemic attack (TIA): Reduced blood flow to the visual cortex or optic pathways can cause sudden, painless vision loss or blurring in one eye.
• Glaucoma: Sudden increases in intraocular pressure (acute angle-closure glaucoma) can cause blurry vision along with eye pain and redness.
• Trauma: Injury to the eye can lead to temporary or permanent blurred vision.

Symptoms

Blurred vision in one eye may be accompanied by other symptoms, depending on the underlying cause:

• Partial or complete loss of sharpness in one eye.
• Floaters or flashes of light in the field of vision.
• Eye pain or discomfort, especially with optic neuritis or infections.
• Redness, tearing, or discharge if caused by infections.
• Distorted or wavy vision, particularly with macular conditions.
• Double vision (monocular diplopia) in one eye.
• Headaches, especially in cases of migraines or stroke.
• Light sensitivity or halos around lights.

Diagnosis

Diagnosing the cause of blurred vision in one eye involves a comprehensive eye examination and sometimes additional testing:

• Eye exam: Visual acuity testing, pupil response, and slit-lamp examination to assess eye health.
• Refraction test: To determine if glasses or contact lenses can correct the blurriness.
• Dilated retinal examination: Allows the doctor to examine the retina and optic nerve for signs of damage or disease.
• Optical coherence tomography (OCT): Imaging of the retina and macula to detect swelling or degeneration.
• Visual field testing: To assess peripheral vision and detect nerve or brain-related issues.
• Blood tests: To identify underlying systemic conditions like diabetes or autoimmune diseases.
• Neuroimaging: MRI or CT scans may be ordered if stroke, TIA, or brain lesions are suspected.

Treatment

Treatment for blurred vision in one eye depends on the underlying cause:

• Refractive errors: Corrective glasses or contact lenses improve vision clarity.
• Dry eyes: Artificial tears, lifestyle changes, or medications to increase tear production.
• Infections: Antibiotic or antiviral eye drops for bacterial or viral infections, respectively.
• Migraines: Rest, hydration, and migraine-specific medications.
• Retinal issues: Surgical interventions like laser therapy or vitrectomy for conditions like retinal detachment or macular holes.
• Optic neuritis: Corticosteroid therapy to reduce inflammation.
• Glaucoma: Medications, laser treatments, or surgery to lower intraocular pressure.
• Stroke/TIA: Emergency medical care, antiplatelet drugs, and addressing cardiovascular risk factors.
• Trauma-related blurring: Depending on severity, may require medical treatment, observation, or surgery.

Prognosis

The prognosis for blurred vision in one eye varies widely based on the cause and how quickly treatment is initiated. In cases caused by refractive errors or mild infections, full recovery is typical with minimal intervention. For inflammatory or neurological conditions like optic neuritis or migraines, vision often improves but may take several weeks.

More serious causes, such as retinal detachment or stroke, require urgent treatment to prevent permanent vision loss. Early diagnosis and prompt treatment significantly improve the chances of vision recovery. Regular eye check-ups and medical follow-up are important, especially for individuals with underlying health conditions like diabetes, hypertension, or autoimmune diseases.