If you’re suddenly experiencing blurry vision in one eye, it is essential to seek medical attention.
There are a number of conditions which might cause blurry sight in one eye, including basic refractive errors and migraines, and more serious concerns like retinal detachment or a stroke.
It’s not uncommon to experience deteriorating vision over time, but if you’re experiencing blurry vision suddenly in one eye, it’s essential to seek medical attention.
A behavioural optometrist in Sydney can help you determine if your sudden blurry vision in one eye is an easy fix, or something of greater concern that requires rapid medical attention.
In this guide, we’ll cover the possible causes of sudden blurry vision in one eye, warning signs to look out for, when to seek medical attention, and the best ways to protect your vision.
What is blurry vision in one eye?
Foggy vision in one eye could mean a lack of clarity, meaning your vision isn’t as sharp as usual and objects appear blurry or out of focus. It could impact your whole visual field, or only parts.
There are a number of possible causes which could be responsible for unclear vision in one eye.
Why is it occurring in only one eye?
Blurry vision in just one eye happens because – to put it simply – your eyes are separate. Even though they work together, one can be impacted while the other stays clear.
When it comes to simple issues, like dry eye, one eye may be more affected because the glands secreting the necessary components of the tear film may be inefficient. Or, if you wear contact lenses, one lens might not be aligning correctly. Refractive errors (like needing glasses or having different prescriptions in each eye) can also make one eye seem blurrier than the other.
Then there are things like infections, minor injuries, or corneal issues, which can happen to just one eye if something irritates it—like rubbing too much or getting dust in it. In some cases, it could be due to nerve or retinal problems, which tend to develop on one side rather than both at once.
Causes of blurry vision in one eye
Foggy vision in one eye suddenly could be caused by a number of underlying issues. If your eyesight is blurry in one eye, it could be down to something as simple as conjunctivitis, or it could be something as serious as a retinal detachment, or even a stroke.
If you have multiple symptoms, like blurry vision in one eye, headache, and arm weakness, this could indicate a stroke, and you should seek medical attention as soon as possible.
– Refractive Errors
You might be seeing blurry in one eye because of refractive errors – one of the most common causes of eye problems. It’s an umbrella term that covers a number of issues – some minor, and some more complex.
These include : myopia (near-sightedness), hyperopia (far-sightedness), astigmatism (distorted vision) and presbyopia (difficulty seeing objects up close).
Blurry vision is the most common symptom, but you may also experience hazy vision, double vision, halos around bright lights, eyestrain, and headaches.
Most refractive issues can be corrected with glasses – your optometrist will be able to diagnose and then assist with any of the above issues.
These are problems that are more likely to develop gradually over time, so if you’ve woken up with sudden blurriness in one eye, something else is likely to blame.
– Amblyopia
Amblyopia, or “lazy eye,” usually develops in childhood and happens when one eye doesn’t communicate properly with the brain. Over time, the brain starts favouring the stronger eye, which can lead to fuzzy vision in one eye.
If you’re an adult and suddenly experiencing blurriness in one eye, it’s not amblyopia—since amblyopia is a condition that forms early in life. However, if you had undiagnosed or untreated amblyopia as a child, you might notice vision issues becoming more noticeable over time.
If one eye has always been a bit weaker but is now suddenly much blurrier, something else might be going on, like eye strain, dry eye, or another vision issue that’s worth getting checked.
– Stroke
The most worrying cause of blurry, cloudy vision in one eye is a stroke. About 65% of stroke survivors experience some degree of vision problems – this can mean blurry vision in one or both eyes.
How severely vision is impacted can depend on the severity of the stroke, the length of time elapsed before seeking treatment, and what part of the brain is affected – damage to the right side of the brain causes changes in the left eye, while damage to the left side will cause vision problems in the right eye.
You should seek immediate medical attention if your blurry vision in one or both eyes has come on suddenly, and is accompanied by other stroke symptoms like :
- Face drooping
- Arm weakness
- Speech difficulty
- Sudden trouble seeing or walking
- A severe headache
Remember that women tend to present with ‘less traditional’ stroke symptoms like generalised weakness, fatigue, mental status change, and disorientation.
Cystoid Macular Oedema
Cystoid macular oedema is a swelling in the macula, the central part of the retina. It can cause blurred vision and vision loss.
- Inflammation after eye surgery, including cataract surgery and repair of a detached retina
- Diabetes
- Blockage in veins of your retina (retinal vein occlusion)
- Inflammation of your eye
- Injury to the eye
- Side effects of medications
Treatments include anti-inflammatory and steroidal eye drops or a steroid injection into the eye.
Retinal vein occlusion
Retinal vein occlusion is a condition that can result in blurred vision, floaters, and decreased sight in one eye.
Retinal vein occlusion can be classified into two primary forms : central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).
CRVO is when the major retinal vein gets blocked, while BRVO involves its more limited branches.
It’s essential to receive medical attention early on as it may help minimise the potential for complete loss of sight.
Symptoms range from mild to severe and might worsen over time, so keeping an eye out for any changes could be beneficial.
Central retinal artery occlusion
Central retinal artery occlusion (CRAO) is a blockage of the main blood vessel that supplies blood to the retina in one eye.
It’s an ophthalmic emergency that can cause sudden and severe vision loss. Symptoms include sudden, painless vision loss in one eye and complete blurring of eyesight in one eye.
The cause of CRAO is usually a blood clot or cholesterol deposit in the blood vessel, carotid artery atherosclerosis, faulty heart valves, tumours in the heart, and abnormal heart rhythms.
Risk factors for CRAO include high blood pressure, aging, diabetes, thicker blood, and the use of the birth control pill in women.
Immediate medical attention should be sought to address the underlying cause and attempt to restore blood flow.
Retinal detachment
Retinal detachment, while not life threatening, is a medical emergency and could result in seriously impaired vision unless treated.
Retinal detachment happens when the retina pulls away from the back of the eye, disrupting its ability to send visual signals to the brain.
This usually causes blurry vision in one eye suddenly – or both. You might also notice :
- A shadow or curtain over part of the visual field
- Flashes of light
- A sudden increase in floaters
Retinal detachment is a serious condition that can lead to permanent vision loss, so it’s imperative that you seek medical attention.
Glaucoma
Glaucoma is the name given to a group of eye diseases where vision is lost due to damage to the optic nerve. It causes irreversible vision loss due to damage to the optic nerve.
The loss of sight is usually gradual and a considerable amount of peripheral (side) vision may be lost before there is an awareness of any problem.
Unfortunately, there is no cure for glaucoma, and vision loss is irreversible. However, acute angle-closure glaucoma can cause sudden blurry vision, severe eye pain, headache, nausea, and halos around lights.
This happens when fluid drainage in the eye is suddenly blocked, increasing eye pressure rapidly. You should see an optometrist as soon as possible.
Macular degeneration
Macular degeneration is the most common cause of vision loss in people over 50.
It’s related to the macula, which is located centrally in the eye – this is why many people report dark or empty spots in the middle of vision.
Those with macular degeneration may also notice :
- Blurry vision spot in one eye, or both, and/or distorted central vision
- Difficulty reading or seeing fine details
- Dark or empty spots in the middle of vision
- Straight lines appearing wavy or bent
- Reduced colour perception
Certain kinds of macular degeneration, particularly those that present with a sudden onset of symptoms, can be dangerous, and should be treated by an optometrist immediately.
Conjunctivitis
Conjunctivitis is also known as pink eye, and it’s an infection of the conjunctiva—the thin, clear tissue that covers the white part of your eye and the inside of your eyelids. It can make your eye look red, irritated, and watery, and is often uncomfortable.
Untreated conjunctivitis can cause you to be blurry in one eye, as a result of:
- Excess mucus or discharge – bacterial or viral conjunctivitis can cause thick discharge that coats the eye and temporarily blurs vision.
- Swelling and inflammation – inflammation of the conjunctiva can cause temporary vision distortion by affecting how light enters the eye.
- Tear film disruption – conjunctivitis can disrupt the tear film, making the surface of the eye uneven and leading to blurriness.
- Corneal involvement – in rare cases, severe viral conjunctivitis (especially from herpes or adenovirus) can spread to the cornea, causing longer-lasting blurred vision.
In addition to blurry vision, you’ll likely notice some redness, itchiness, and discharge.
Cataract
Cataracts are a clouding of the eye’s natural lens, which leads to blurry, hazy, or dim vision. While you might experience blurry vision, cataracts tend to be gradual, rather than sudden.
Some people describe the vision impact as looking through a foggy window. There are other symptoms to look out for, like increased light sensitivity, impaired night vision, faded colours, and halos around lights.
Cataracts develop at different rates for each eye, which can mean experiencing blurry vision in just one eye.
Eye strain
Eye strain can sometimes cause blurry vision in one eye, though it usually affects both. If only one eye is overworked—due to an uneven prescription, excessive screen time, or prolonged focus—it can lead to temporary blurriness, discomfort, or fatigue in that eye.
Eye strain is usually temporary, and will improve with rest, but an optometrist can help determine what might be causing serious or prolonged blurriness from eye strain.
Migraine
If you have blurry vision in one eye and headache, it could be a migraine. Migraines, especially ocular migraines and migraine with aura, can cause blurry vision, sometimes in just one eye. If you’ve never had a migraine before, look for other symptoms like :
- A throbbing headache (on one side of the head)
- Nausea or vomiting
- Sensitivity to light and sound
- Worsens with movement
The best treatment for a migraine is rest – lie down in a dark, quiet room, avoid screens, stay hydrated and try warm and cold compresses.
Diabetes
High blood sugar levels can cause swelling and fluid fluctuations in the eye, which leads to blurry vision.
This can be an early sign of diabetic eye disease, and can lead to permanent vision problems, so it’s essential that you monitor any vision changes closely and consult a doctor.
Dry Eye Syndrome
If the cause is dry eyes, you’re more likely to experience blurriness in both eyes.
That being said, it’s possible to experience blurriness in one eye if you have a blocked tear duct, or just one eye isn’t adequately lubricated.
If this is the cause, you’ll likely also experience a scratchy sensation, itchiness and general irritation.
Warning signs to look out for
Blurry vision in one eye isn’t as concerning as sudden blurry vision in one eye. If you’ve woken up with seriously impaired vision, then something is amiss. Do not delay seeking medical attention.
The main determination is if your blurry vision is related specifically to your eyes, or is a symptom of a larger problem. If your blurry vision is the result of dry eyes or conjunctivitis, you’ll likely have other eye-specific symptoms, like redness or irritation.
However, if your blurry vision stems from a larger problem, like a stroke, you’ll experience other symptoms, like face drooping or arm weakness.
Here are the main warning signs to look out for :
- Sudden or severe vision loss
- Flashes of light or floaters
- Eye pain or headache
- Dark curtain or shadow over vision
- Double vision
- Facial drooping, slurred speech, or weakness
When to seek medical attention
Unless you’re confident that your blurred vision in one eye is caused by a minor, temporary issue like eye strain, you should seek medical attention. This is especially true if the vision impairment has come on suddenly.
However, if you don’t have any of the warning signs mentioned above, you should continue to monitor the situation and seek medical attention if :
- Your vision continues to gradually worsen, as this could be due to cataracts, diabetic retinopathy, or macular degeneration.
- You experience redness and discharge, as this may indicate an infection like conjunctivitis or keratitis.
- You suffer from eye strain or discomfort, as this could be due to dry eye, refractive errors, or migraines.
- You see halos around lights, as this is a possible symptom of glaucoma or corneal problems.
Treatments for blurry vision in one eye
The treatment is entirely dependent on the cause – it goes without saying that the treatment for glaucoma varies wildly from the treatment for a stroke.
Your optometrist can help you determine what’s causing blurry sight in one eye, how to treat it, and – if applicable – how to stop the issue from recurring.
Here are treatments for some of the conditions we’ve covered :
| Cause | Possible Treatments |
|---|---|
| Refractive Errors (e.g., myopia, hyperopia, astigmatism) | Glasses, contact lenses, LASIK surgery |
| Amblyopia (lazy eye) | Vision therapy, corrective lenses |
| Stroke | Emergency medical care, blood thinners, rehabilitation therapy |
| Retinal Detachment | Urgent surgery (laser therapy, vitrectomy, scleral buckle) |
| Glaucoma | Prescription eye drops, laser treatment, surgery to reduce eye pressure |
| Macular Degeneration | Anti-VEGF injections, lifestyle changes, vitamin supplements (AREDS2) |
| Cataract | Surgery to replace the cloudy lens with an artificial one |
| Eye Strain | Reducing screen time, blue light filters, taking breaks, lubricating drops |
| Migraine | Rest, hydration, avoiding triggers, migraine medications |
| Diabetes (Diabetic Retinopathy) | Blood sugar control, laser treatment, anti-VEGF injections |
| Dry Eye Syndrome | Artificial tears, warm compresses, omega-3 supplements, prescription drops |
How can I protect my vision?
The best treatment is prevention. Sticking to regular check-ups means your optometrist can spot any problems before they become more serious. In general, you should see an optometrist every 1-2 years.
This way, your optometrist can monitor your vision for any changes or deterioration, make changes to your glasses prescription before eye strain occurs, and keep track of warning signs of glaucoma and other eye diseases – this is doubly true if you have a family history of eye disease.
Other ways to protect your vision include :
- Wearing sunglasses to reduce sun damage
- A healthy diet, rich in omega 3 (fatty fish and flaxseed oil) as well as dark green leafy vegetables, orange and red fruit and vegetables.
- If you spend a lot of time in front of a screen, follow the 20-20-20 rule: every 20 minutes, look 20 feet away for 20 seconds to reduce eye strain
- Quit smoking, as this will reduce the risk of eye diseases like cataracts and macular degeneration
- Get enough sleep and drink enough water
- Get regular exercise – this combats high blood pressure, which can harm your vision
- Avoid reading or working in dim light, as this can cause eye strain
With over 30 years of experience, OptimEyes can help you achieve and maintain healthy vision. Whether it’s treatment for blurry vision, prescription glasses, or a referral to an ophthalmologist for more complex care, our experienced team is here to guide you.
Call today to book an appointment with OptimEyes.
FAQ’s
1. Does blurred vision in one eye mean a stroke?
Blurred vision is a symptom of stroke, but having blurred vision doesn’t always mean a stroke. You need to look at the whole picture. Did your blurry vision come on suddenly, or slowly?
If it has come on over a matter of weeks or months, then a stroke is unlikely to be the cause.
To be safe, you should look out for other signs of a stroke, like face drooping, arm weakness, speech difficulty, sudden trouble seeing or walking, or a severe headache.
Women tend to experience more generalised symptoms, and should look out for weakness, fatigue, mental status change, or disorientation.
If you have the above symptoms, in conjunction with blurry vision in one eye, then you should seek medical attention as soon as possible.
2. Can stress cause blurry vision in one eye?
Yes, the body’s stress response can impact blood flow and muscle tension around the eyes, resulting in blurred vision – this is due to spiked cortisol and adrenaline. While this can be scary, it is temporary – once your stress hormones reduce, your normal vision will return.
Try the 5-4-3-2-1 grounding technique – this will help bring your focus back to the present moment and away from anxious thoughts, which should correct any stress-related vision problems.
How to do it:
- 5 – Notice five things you can see (a tree, your hands, a book).
- 4 – Notice four things you can hear (birds chirping, a clock ticking).
- 3 – Notice three things you can touch (your clothes, a chair, a warm mug).
- 2 – Notice two things you can smell (coffee, fresh air).
- 1 – Notice one thing you can taste (gum, toothpaste, a sip of water).
3. Can dehydration cause blurry vision?
Yes – when you’re not drinking enough water, your body struggles to produce enough tears, leading to dry eyes, irritation, and, in some cases, blurry vision.
Dehydration can also impact your blood pressure and circulation, which may reduce the amount of oxygen reaching your eyes. For healthy eyes and body, drink about two litres of water a day – although this should be more if you’re active or live in a warm climate.
4. Can high blood pressure cause blurry vision?
Yes, high blood pressure can cause blurry vision. This is because high blood pressure puts extra strain on the tiny blood vessels in your eyes. Over time, this can lead to damage in the retina (hypertensive retinopathy), fluid buildup under the retina, or even optic nerve damage.
You can reduce your risk for high blood pressure (and protect your vision) by engaging in regular exercise, eating a balanced diet rich in fruits, veggies, and whole grains, cutting back on salt and processed foods, staying hydrated, managing stress, and keeping an eye on your alcohol and caffeine intake.
Plus, don’t forget regular check-ups—both for your blood pressure and your eyes!
5. Why is my vision in one eye suddenly gone?
There could be down to a number of causes, including stroke, but if you are experiencing a rapid change in your vision, you should seek medical attention as soon as possible.
6. What eye drops are good for blurry vision?
If your vision’s gone a bit blurry, the right eye drops depend on what’s causing it.
- For dry eyes, try Cationorm, Hylo-Fresh, or Hylo-Forte.
- For allergies, try Zaditen or Albalon A.
- If you have eye strain from staring at screens for too long, then lubricating drops might do the trick, but regular breaks are key.
For glaucoma or presbyopia, it may be necessary to seek prescription eye drops from an optometrist or ophthalmologist.
7. How long does blurry vision last?
How long blurry vision lasts will depend on the cause – blurry vision resulting from eye strain or conjunctivitis is temporary, while blurry vision caused by glaucoma is more likely to be long lasting.
Your optometrist can help determine a treatment plan to get your vision back on track.
8. How do you fix blurry vision in one eye?
There’s no one-size-fits-all solution – the treatment will depend on the cause, and blurry vision in one eye can be caused by a number of underlying conditions, from glaucoma to retinal detachment.
If your blurry vision is caused by refractive issues, then this will likely be addressed with contact lenses.
Wet macular degeneration will be treated with anti-VEGF injections, lifestyle changes and vitamin supplements, cataracts may require surgery, and eye strain can be addressed simply by reducing screen time and taking regular breaks.
