Sudden blurry vision in one eye can be a disconcerting experience, often prompting immediate concern. This symptom, where objects appear fuzzy or out of focus in only one eye, can arise from various underlying issues. While some causes are temporary and relatively minor, others may indicate a more serious condition that requires prompt medical attention. Understanding the potential reasons behind this visual change is an important first step toward addressing the symptom.
Common Reasons for Sudden Blurry Vision
Less severe causes often stem from daily activities or minor irritations. Dry eye syndrome, a common condition, leads to blurry vision when an unstable tear film prevents light from focusing clearly on the retina. This happens as tears evaporate too quickly or are insufficient, disrupting vision. Eye strain, often from prolonged screen use or reading, can also cause temporary blurriness as eye muscles fatigue and blinking decreases.
Ocular migraines present as brief visual disturbances in one eye, including temporary blind spots, shimmering lights, or zigzag patterns, with or without a headache. A minor corneal abrasion, a scratch on the eye’s surface, can also cause sudden blurry vision. Similarly, a foreign body like dust or an eyelash can irritate the cornea, leading to blurriness and a feeling of something in the eye. Certain medications may also temporarily affect vision, causing dry eyes or altered focusing.
Serious Conditions Requiring Prompt Attention
Some instances of sudden blurry vision in one eye point to urgent medical conditions requiring immediate evaluation. Retinal detachment occurs when the retina pulls away from its supporting layers, potentially leading to permanent vision loss if untreated. Symptoms often include flashes of light, new floaters, or a sensation of a curtain obscuring vision. Optic neuritis, an inflammation of the optic nerve, causes sudden vision loss or blurriness, often with pain upon eye movement.
Acute angle-closure glaucoma is a medical emergency characterized by a sudden increase in eye pressure. This can quickly damage the optic nerve, leading to blurry vision, eye pain, headache, and sometimes nausea or vomiting. A stroke or transient ischemic attack (TIA) may also cause sudden blurry vision in one eye due to disrupted blood flow to the brain or eye. This can occur with other neurological symptoms like numbness, weakness, or speech difficulty. Temporal arteritis, an inflammatory condition affecting blood vessels, including those supplying the optic nerve, can cause sudden vision loss in one eye. Blockages in the retinal artery or vein (retinal artery occlusion or retinal vein occlusion) can also abruptly impair vision by cutting off blood supply or drainage to the retina.
Responding to Sudden Blurry Vision
If you experience sudden blurry vision in one eye, avoid self-diagnosing or rubbing it. Try resting your eye to see if the blurriness resolves. If accompanied by severe eye pain, sudden vision loss, or symptoms like a severe headache, double vision, weakness, or numbness on one side of the body, immediate emergency medical attention is necessary. These additional symptoms can signal a serious underlying condition.
Flashes of light, new or increased floaters, or a dark “curtain” coming across your vision also warrant urgent medical evaluation. If the blurriness is sudden but without these severe accompanying symptoms, contact an eye care professional, such as an ophthalmologist or optometrist, promptly. They can determine the cause and recommend appropriate next steps, even if the situation does not require an emergency room visit.
Medical Evaluation and Treatment
A medical evaluation for sudden blurry vision typically begins with a comprehensive eye examination. This often includes checking visual acuity, assessing eye pressure, and performing a slit lamp examination to view the front structures of the eye. A dilated fundus examination allows the doctor to inspect the retina and optic nerve at the back of the eye. Depending on initial findings, additional tests may be necessary.
Further diagnostic tools can include optical coherence tomography (OCT) for detailed retinal images, visual field tests for peripheral vision, or neurological imaging like MRI or CT scans if a systemic cause like a stroke is suspected. Treatment approaches vary widely and are tailored to the specific diagnosis. These can range from eye drops or oral medications for inflammatory conditions or infections to laser procedures or surgery for conditions like retinal detachment or acute angle-closure glaucoma. For blurry vision as a symptom of a broader systemic disease, managing the underlying medical condition is central to the treatment plan.