17 Causes of Sudden Blurred Vision in One Eye

Often, our eyes get blurry, and we start losing focus. While this is not a problem in itself, it might be a sign you have poor vision or that you have an eye condition worth checking. In that case, the first step should be going to a doctor, so you get a professional diagnosis, if you don’t have a condition, maybe you could try some eye exercises to improve your eyesight.

Even though blurry vision has been related to aging, it might occur at any age. And like most eye problems, it’s a gradual process that can be stopped or staved so as the eye doesn’t lose its functionality.

From a medical perspective, the loss of vision in one or two eyes and the focusing ability of the eye is called presbyopia, which is the medical term that signals a “decreased visual acuity in one eye,” that affects the pupil and the retina, decreasing the amount of light that enters into the eye and causing blurry vision.

Blurry vision in one or two eyes is, actually, the most common eyesight problem, and while it’s often nothing to worry about, it’s always better to be safe than sorry. 

Also, it’s also possible for a person to experience sudden blurred vision in one eye, and it might be caused by several conditions that range from glaucoma, cataracts, macular degeneration, uncorrected refractive errors, and age-related conditions.

On the brighter side, more often than not, the causes of blurred vision in one eye can be excessive tear production due to stress, dust, debris, or even from rubbing excessively.

Similarly, the aging of the world’s population has lead to a substantial increase in the number of individuals with sequelae of eye-related diseases and injuries. 

Today’s article focuses on how to spot and treat sudden blurred vision in one eye before it turns into a problem, and help you handle and slow it in you’re already experiencing it.


Table of Contents

  • 14 Symptoms of Sudden Blurred Vision in One Eye
  • 17 Causes of Sudden Blurred Vision in One Eye
  • How To Treat Sudden Blurred Vision in One Eye

14 Symptoms of Sudden Blurred Vision in One Eye

Sight is one of the most valued senses we have, and any sign that you’re losing it is a warning sign. We experience most of the world through our eyes and not being able to see correctly is something we don’t even want to think of.

Imagine for a second how your perception of everything around you would change if you couldn’t see what’s around you.  

Always investigate what’s causing your blurry vision. Knowing the reasons behind your problem can make a world of difference because it can also help you slow the progression of the conditions you might be suffering. 

Blurred vision, particularly when it’s only in one eye, can be the result of a wide array of conditions such as infections, corneal abrasions, neurological concerns, and degeneration. Also, when blurred vision develops over time, it might be associated to changes to the shape of the eye or the cornea; if that happens, you should visit your doctor’s office and get some test done.


1. Watery eyes

Normally, tears drain into your nose and through tiny openings in the eyelids and watery eyes have no relation with the retina or the front of your eyes. However, in adults, especially older ones, watery eyes can cover a wide range of conditions ranging from natural aging and sagging of the eyelids to problems in your cornea.


2. Double or Triple Vision in One Eye

Also known as diplopia, this condition occurs when one eye looks at one object but sees two images, severely impairing your vision. While double vision affecting your eye is less common, it’s usually caused by problems such as dry eye syndrome, astigmatism, cataracts, and keratoconus.


3. Squinting

More often than not, our natural answer to blurry vision in one or both eyes is to squint. When we squint, we refocus or vision to see better. Nevertheless, squinting could be a symptom of refractory errors in the eye.


4. Cloudy Vision

Let’s start by saying that cloudy vision and blurred vision are not the same. Even though the terms are used interchangeably, they are different conditions. Cloudy vision is a gradual loss of the transparency of the cornea or the lens of the eye, which is a common symptom of cataracts and can occur as a result of injuries, diabetes, or certain medication.


5. Eye Pain

Although common, eye pain isn’t dangerous unless you start to lose your vision. It can be described as the feeling of “having something in your eye,” an ache, a pressure, or a throbbing sensation. Ocular pain often occurs only on the eye’s surface, and orbital pain is often experienced within the eye. Eye pain is often confused with headaches, sinus pain, and even migraine and you should go to the doctor if you experience worse symptoms


6. Headaches

The eye and the brain are inextricably linked, and often your headaches will be associated with vision problems. Medical research has established that headaches are often ophthalmic; at the same time, other kinds of vision problems such as retro-orbital pains are often confused with simple headaches. For that reason, physicians recommend a visit to the ophthalmologist if you’re experiencing head pain.


7. Joint Pain or Stiffness

It turns out that arthritis can also affect your eyes, particularly the sclera and cornea, which are almost entirely made of collagen. For instance, the inflammation of the sclera caused by arthritis can thin the eye wall, causing inflammation, sensitivity to light, and reduced vision.


8. Bleeding or Discharge from Your Eye

The conjunctive tissue is the thin, transparent, and moist membrane that covers the sclera (the white part of your eye). This tissue contains the nerves and the blood vessels of your eye, which are barely visible unless the eye is inflamed. When the eye is too inflamed, they break and can cause subconjunctival hemorrhage, which looks like a bright dark spot on the sclera or results in a bloody discharge from your eye. 


9. Red Eyes

The causes of red eyes are extremely varied and could range from allergies to glaucoma and while might look alarming, they are often a minor eye condition such as conjunctivitis but could also mean a burst blood vessel. If your eyes are red and you’re feeling pain, see your doctor as it could mean a serious health hazard.


10. Dry or Itchy Eyes

Dry eye syndrome is one the most common eye conditions, and it’s often caused by a chronic lack of lubrication and moisture on the surface of the eye. Dry eye ranges from a subtle but constant irritation to inflammation and scarring of the front of the eye. Dry eyes often cause a scratchy sensation or feeling that something is in the eye, stinging, or burning in the eye that could cause episodes of tearing that then cause extreme dryness.


11. Increased Sensitivity to Light

We all are sensitive to light to some degree, but a light sensitivity or photophobia is an abnormal intolerance for light. Sunlight and other light sources can affect your eyes and can cause you to squint or even close your eyes. Photophobia can cause pain and excessive tearing that could also cause headaches.


12. Poor Night Vision

Let’s face it; humans are not meant to see in the dark. But deterioration of your night vision can be dangerous, particularly if you’re driving. Many people find that, at night, headlights and traffic lights can be debilitating or even cause distortion. You can correct this problem by wearing prescription lenses with anti-glare coating, but it can also come from more than refractive errors and could include glaucoma cataracts, or vitamin A deficiency. 


13. Seeing Spots or "Floaters"

People who experience floaters can see faint black or gray areas in their vision. Floaters are those shapes you see that are dots, specks, clouds, or many other things. Often, spots are caused by irregularities in the vitreous get that fills your eye. This irregularity casts a shadow onto the retina, blocking small areas of your vision and causing these “floaters.”


14.Central or Peripheral Vision Loss

Central or peripheral vision loss in one eye is often caused primarily by age-related macular degeneration. When a person suffers from macular degeneration, it can develop a different fixation point to cope with the disease. Central or peripheral loss of the vision could also be due to “eye strokes” that block the normal blood to the eye’s internal structures, which could lead to injuries.


17 Causes of Sudden Blurred Vision in One Eye


1. Refractive Errors

Refractive errors occur when the shape of the eye prevents light from focusing on the retina. This can happen due to genetic factors or aging. The most common refractive problems that cause sudden blurred vision are myopia, astigmatism, hyperopia, and presbyopia. Most refractive errors


2. Conjunctivitis

Conjunctivitis can be viral, bacterial, or allergic and most of us have suffered from it at least once.  Usually, conjunctivitis involves a mucopurulent discharge from the eye, stuck lashes on waking, and discomfort. In this case, blurred vision can happen in one eye or both due to the disturbance of the tear film. If the blurred vision persists after blinking, there might be corneal involvement.


3. Cataracts

Most people will experience cataracts during their lives and, over time, cataracts will blur your vision significantly, preventing from doing the activities you enjoy. Cataracts often start as a milky spot in the eye and grow towards your iris, clouding your sight. In that case, there are medical procedures you could opt for, but cataracts’ progress can be slowed with exercises and supplements, too.  


4. Eye Infections

Contact lenses-induced eye infections are pretty common, and while they can be easily treated, some of them can cause sudden blurred vision. Be mindful of your contact lenses and make sure you don’t sleep with them on, or don’t wear them while swimming. Unproperly cared for contacts can cause infections that could put your vision at risk.


5. Glaucoma

The two most common forms of glaucoma are open-angle glaucoma and angle-closure glaucoma. Open-angle is often called “the sneak thief of sight” because it shows no symptoms until significant loss of vision in one eye occurs. Since most of the patients who suffer glaucoma don’t notice changes or blurry vision until it’s too late to be reversed, regular examinations are crucial to detecting it.

6. Keratoconus

Keratoconus is a disease that causes a bulging and thinning of the cornea, deflecting the light and causing blurred or distorted vision. Keratoconus often starts in the late teens and the twenties and can progress unnoticed unless you go to an ophthalmologist.


7. Age-Related Macular Degeneration

AMD blurs the sharp, central vision you need to read, drive, sew or activities that require you see straight ahead. This degenerative disorder affects the macula, the part of the eye you need to see things in fine detail and although it causes no pain, AMD is a severe condition that severely impacts your ability to go on with your daily activities.

8. Diabetic Retinopathy

Diabetic retinopathy occurs only in people with diabetes and causes progressive damage to the retina. Retinopathy is one of the most serious complications of diabetes and starts with the sudden blurring of one or two eyes. Over time, diabetes damages the blood vessels in the retina, causing the tissue to swell, blurring the vision. If left untreated, it can cause diabetes.


9. High Blood Pressure

High blood pressure can also cause retinopathy, causing internal bleeding, sudden blurred vision in one eye, and loss of sight. Blood pressure can also cause choroidopathy, which is a fluid buildup under the retina that distorts vision.


10. Heart Attack

A stroke is an episode of decreased blood flow to the brain which can be caused by a blockage or damage to a blood vessel, preventing the brain from receiving blood. This event could cause blurred or decreased vision due to damage to the optic nerve. It can also cause double vision in one eye and damage to the nerves responsible for moving the eyes.


11. Preeclampsia

While this only concern 5-8% pregnant women, it includes high blood pressure which can trigger gestational hypertension. Severe preeclampsia can cause headaches, blurred vision, high sensitivity to light, fatigue, and nausea. Since preeclampsia is silent, a proper control during pregnancy is necessary to prevent similar episodes.


12. Migraine

Apart from being painful, bothering episodes that could cause changes in the senses. A migraine can also cause blurred vision in one eye. In fact, migraine sufferers may experience blurry vision, vision loss, and eventually pain. Migraines with aura are more often the cause of visual changes and subside after a while.


13. Uveitis

This condition, caused by an inflammation of the uvea, which is the pigmented layer between the inner retina composed of the sclera and the cornea. Since the condition causes inflammation, it could be a cause of blurry vision and requires an urgent ophthalmic treatment to control the inflammation.


14. Multiple Sclerosis

In some people with multiple sclerosis,  the nerve pathways that control the movement of the eyes can be affected, causing the eyes not to move smoothly, be out of alignment, and result in blurry vision. MS can cause optic neuritis which blurs and clouds the affected eye.


15. Optic Neuritis

Optic Neuritis is the sudden loss of vision in one or two eyes, sudden blurred vision, and pain in one eye. Like we mentioned above, it’s often caused by MS and includes partial vision loss or episodes of disturbed vision that indicate a moderate onset of the illness, requiring immediate medical attention to prevent further loss of vision.


16. Use of Atropine

Atropine is the chemical compound that causes the muscles in your eye to become relaxed, and it’s often used by the ophthalmologist to dilate your pupil. In general terms, atropine can cause your eye to not to focus correctly and your vision to blur. Atropine is also used to treat lazy eye, placing a few drops in the strong eye to make the “lazy” one focus.


17. Hypervitaminosis

Hypervitaminosis A or vitamin A toxicity occurs when you have too much vitamin A in your body. While vitamin A could improve your vision, too much of it could cause blurry vision in one eye, double vision in one eye, nausea, vomiting, dizziness, and a plethora of unwanted consequences. So try not to exceed the recommended doses.


How to Treat Sudden Blurry Vision in One Eye  

While there are many causes behind your vision getting blurry, the first advice we can give you is to not act on it yourself without getting professional counsel. An eye professional has the tools to help you to make sure your vision stays healthy.


Visit Your Doctor

This is the first step to treat any type of blurry vision-related condition. An ophthalmologist can help you diagnose the underlying cause of your problem, take corrective measures to fix it before it becomes a problem, or treat it before it gets worse. Your doctor will run a battery of tests and find the right diagnosis for you and, luckily, you’ll regain your vision.

There are a few of different test your doctor could use to determine the cause of your blurry vision in one or both eyes. These tests include:

Slit-Lamp Examination

A slit lamp is a lamp that shoots a slit-like beam of light to your eye while you stare at an object. In this case, the doctor will dilate your pupil to diminish your photosensitivity.

Refraction Test

In this case, the doctor will measure your need for prescription glasses; here, the doctor will have you read letters from a board, also called the Snellen test while switching lenses to see which helps you see the clearest.


This test measures your eye pressure, and it’s attached to the slit lamp, so both procedures are done simultaneously. Don’t worry; it doesn’t hurt.

Wear Corrective Glasses

This is the second step to improve your vision after you’ve been diagnosed. If your doctor prescribed you corrective glasses, it’s because your blurry vision is related to a refractive issue or maybe lenses could help you see better. If that’s the case, an optometrist could guide you further in your search for the adequate pair of glasses

Do Exercises to Improve Your Vision

Exercises could help you strengthen your vision and when done adequately can help you combat refractive problems, prevent cataracts and slow the onset of glaucoma.

The chances are that eye exercises are a good idea for you, but it’s better to be safe than sorry. You can go to an ophthalmologist or an optometrist to get a professional opinion. They could even guide you to the journey of improving your eyesight.

In the end, the adequate treatment for your blurred vision depends on the underlying condition. While the eye doctor can treat your eyes, you need to see other physicians if your condition is not directly caused by an eye problem, which means that the steps to change it can be different.

Living a healthy life and reducing fatigue and tiredness is also important, as well as getting enough sleep.


GoodLifeProvision is not a doctor, and this information shouldn't ever substitute professional medical advice, diagnosis, or treatment. If you have questions, seek the help of your physician or qualified health provider. Do not ever disregard professional advice or treatment because of something you have read here. 

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