Monocular blurry vision, or blurry vision in one eye, is a common experience that can range from a minor annoyance to a symptom of a serious health concern. This condition means one eye struggles to see details clearly, even if the other eye maintains sharp vision. While it often signals a need for an updated eyeglass prescription, it can sometimes indicate an underlying medical issue requiring prompt attention.
Common Reasons for Blurry Vision in One Eye
Many instances of monocular blurry vision stem from common, less severe conditions. Eye strain from prolonged screen use or reading can cause temporary blurriness, often with dry eyes, headaches, or eye fatigue. Dry eyes, due to reduced blinking, can also cause intermittent blurriness.
A foreign object, like dust or an eyelash, can cause blurry vision, pain, redness, and a scratchy sensation. If not removed, a foreign body can potentially lead to infection or scratching of the cornea. Minor eye infections, such as conjunctivitis (pink eye), can cause redness, discharge, and blurry vision. Changes in an eye prescription, including astigmatism, can also lead to distorted or blurry vision in one eye.
Urgent Medical Concerns
Certain conditions represent urgent medical concerns requiring immediate evaluation. Retinal detachment occurs when the retina, the light-sensitive tissue at the back of the eye, pulls away from its supporting layers. This can lead to sudden blurry vision, increased floaters, flashes of light, or a shadow in the visual field. Without prompt treatment, permanent vision loss can occur.
Certain types of glaucoma, especially closed-angle glaucoma, can cause a sudden, severe increase in eye pressure, leading to blurry vision, intense eye pain, headache, nausea, and halos around lights. This is considered an eye emergency. Optic neuritis involves inflammation of the optic nerve. This typically causes pain with eye movement, blurry vision in one eye, and faded colors.
Blurry vision in one eye can also signal a stroke or transient ischemic attack (TIA). These involve disrupted blood flow to the brain, potentially affecting visual processing. Accompanying symptoms may include sudden weakness or numbness on one side, difficulty speaking, or balance problems. A corneal ulcer, an open sore on the eye’s surface, can cause blurry vision, redness, severe eye pain, light sensitivity, and discharge. Corneal ulcers require immediate medical attention to prevent severe vision loss or permanent eye damage.
Knowing When to Seek Professional Help
Seek immediate medical evaluation if blurry vision appears suddenly in one eye, especially with eye pain. Other urgent symptoms include sudden flashes of light, new or increased floaters, or a shadow spreading across your vision, which can signal a retinal detachment.
If blurry vision occurs with symptoms suggesting a stroke or TIA (sudden weakness/numbness on one side, difficulty speaking, balance problems), contact emergency services immediately. Severe eye pain, redness, or discharge, especially if vision is affected, may indicate a serious infection like a corneal ulcer. For gradual changes or less severe symptoms like occasional blurriness from eye strain or dry eyes, schedule a routine eye exam.
What to Expect During a Medical Evaluation
During a medical evaluation for blurry vision in one eye, a healthcare provider or ophthalmologist will discuss your symptoms, including onset and duration. A comprehensive eye examination will follow, checking visual acuity and eye pressure. A slit-lamp examination allows the doctor to view the eye’s front and internal structures. Depending on the suspected cause, pupils might be dilated for a thorough view of the retina and optic nerve. Treatment will be tailored to the identified underlying condition.