Why is my vision blurry in one eye?

Suddenly realizing that the world looks clear through one eye but blurry through the other can be a deeply unsettling experience. Your mind might race with questions: Is this serious? Will it go away on its own? What should I do?

If you’re experiencing blurry vision in just one eye, the first and most important thing to know is this: you should not ignore it.

While the cause can be as simple as needing a new pair of glasses, it can also indicate an underlying health condition requiring prompt medical attention, such as the need for doven øjenbehandling. This comprehensive 2025 guide will walk you through the potential causes, from the common to the critical, and provide a clear action plan.

Part 1: The Most Common Culprits – Simple Refractive Errors

For the vast majority of people, blurry vision in one eye is caused by a “refractive error.” This simply means the shape of your eye prevents it from focusing light correctly onto the retina, the light-sensitive tissue at the back of your eye. It’s possible to have a different refractive error in each eye, causing one to see more clearly than the other.

• Myopia (Nearsightedness): This is when distant objects appear blurry while near objects remain clear. You might have a higher degree of myopia in one eye.

• Hyperopia (Farsightedness): This can cause near objects to look blurry. In some cases of higher hyperopia, distant objects can also be blurry as the eye struggles to focus.

• Astigmatism: This occurs when your eye’s cornea is shaped more like an oval than a sphere. This irregularity causes light to focus at multiple points, leading to distorted or blurry vision at all distances. It’s very common for the degree of astigmatism to differ between the two eyes.

• Presbyopia: This is the age-related loss of near-focusing ability that typically starts after age 40. While it affects both eyes, it can sometimes be noticed more in one eye initially.

The Solution: A comprehensive eye examination by an optometrist or ophthalmologist can easily diagnose these issues. The solution is typically corrective lenses (glasses or contact lenses) tailored to your specific prescription.

Læs også: 12 øvelser til at korrigere et dovent øje (amblyopi)

Part 2: When Blurriness Develops Over Time – Chronic or Developmental Conditions

If the blurriness has been a long-standing issue or has developed gradually, it may be related to an underlying condition.

• Amblyopia (Lazy Eye): This is a critical cause to understand. Amblyopia is a developmental condition where the brain-eye connection for one eye doesn’t mature properly in childhood. The brain learns to favour the stronger eye and suppress the image from the weaker (amblyopic) eye, causing it to become blurry. While often diagnosed in kids, many adults live with undiagnosed or undertreated amblyopia, assuming it’s just a “weak eye” they have to live with. As we’ll discuss later, this is no longer the case.

• Grå stær: This is a gradual clouding of the eye’s natural lens, which sits behind the iris. It can feel like looking through a foggy or dusty window. Cataracts are a very common part of aging but can also be caused by injury or other medical conditions. They can develop more quickly in one eye than the other.

• Diabetic Retinopathy: For anyone with diabetes, this is a crucial consideration. High blood sugar levels can damage the tiny blood vessels in the retina, leading to swelling, leaking, and blurry vision. It’s a leading cause of blindness but can be managed with early detection and control of diabetes.

• Age-Related Macular Degeneration (AMD): This condition affects the macula, the central part of the retina responsible for sharp, detailed vision. A key early symptom is distorted vision (straight lines appearing wavy) or a blurry spot in your central vision.

Part 3: Sudden Blurriness – A Sign to Seek Immediate Medical Attention

This is the most important section of this guide. If the blurry vision in one eye appears suddenly, is severe, or is accompanied by any of the following symptoms, treat it as a medical emergency. Go to an emergency room or contact an ophthalmologist immediately.

• Pain in the eye
• Flashes of light or a sudden increase in “floaters”
• A dark curtain or shadow falling across your field of vision
• Dizziness, weakness on one side of your body, or difficulty speaking

These could be signs of:

• Retinal Detachment: A sight-threatening event where the retina pulls away from its normal position.
• Eye Stroke (Retinal Artery Occlusion): A blockage in one of the blood vessels that supply the retina, cutting off its oxygen supply.
• Acute Angle-Closure Glaucoma: A sudden, dangerous spike in eye pressure that can damage the optic nerve.
• Optic Neuritis: Inflammation of the optic nerve connecting the eye to the brain.
• A Transient Ischemic Attack (TIA) or Stroke: Sudden blurry vision can be a symptom of a stroke affecting the vision centers of the brain.

Anbefalet læsning: Sådan retter du et dovent øje: En komplet guide til doven øjenbehandling for voksne

The Solution for a Specific Cause: Advanced Treatment for Amblyopia

Let’s return to amblyopia. If a comprehensive exam by your doctor confirms that your lifelong blurry vision in one eye is due to a “lazy eye,” it’s crucial to know that the old belief that it’s untreatable in adults is now completely outdated.

Here in 2025, modern, brain-based therapies are providing new hope and real results. Bynocs offers a cutting-edge, software-based dichoptic vision therapy program. This therapy uses specialized video games, played while wearing patented glasses, to retrain the adult brain. It forces the brain to stop suppressing the lazy eye and start using both eyes together as a team, effectively reducing the blur and often leading to dramatic improvements in vision and even the emergence of 3D depth perception.

If amblyopia is the diagnosed cause of your blurry vision, Bynocs represents an advanced and effective treatment path available today through certified providers.

Your Undeniably Next Step: See an Eye Doctor

This guide offers potential reasons for your symptom, but it is not a substitute for a professional medical diagnosis. Trying to self-diagnose can be dangerous and may delay sight-saving treatment.

What to Expect at a Comprehensive Eye Exam: to demystify the process, a thorough exam with an ophthalmologist will likely include:

• A visual acuity test (reading the eye chart).
• Refraction to determine your exact prescription.
• A slit-lamp exam to view the structures at the front and back of your eye.
• Tonometry to measure your eye pressure.
• Pupil dilation to allow the doctor a clear view of your retina and optic nerve.

Your Questions Answered: A Quick FAQ

Q: Can stress or fatigue cause blurry vision in one eye?

Yes, high levels of stress, anxiety, and fatigue can sometimes cause temporary blurry vision, often due to eye strain or dry eyes. However, you should never assume stress is the cause without ruling out other medical conditions with your doctor.

Q: What’s the difference between an optometrist and an ophthalmologist?

An Optometrist is a primary eye care professional who can perform eye exams and prescribe glasses/contact lenses. An Ophthalmologist is a medical doctor (an eye surgeon) who can perform all the same functions, but can also diagnose and treat all eye diseases and perform surgery. For sudden or unexplained blurry vision, seeing an ophthalmologist is recommended.

Q: My vision in one eye gets blurry, then goes away. What could it be?

Intermittent blurry vision can be caused by dry eye syndrome, eye strain from digital devices, or fluctuations in blood sugar. However, it can also be a sign of a Transient Ischemic Attack (TIA or “mini-stroke”), so it should always be investigated by a doctor.

Conclusion: Don’t Guess, Get Checked

Your vision is one of your most precious senses. While the reason for blurriness in one eye is often simple, the potential for it to be something more serious makes a professional evaluation non-negotiable.

Don’t wait and wonder. Take decisive action. Schedule an appointment with an ophthalmologist to get a definitive answer and a proper treatment plan for your specific needs.