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Common causes for blurry vision

What does blurry vision appear like? 

Our eyes are changing constantly, based on environmental factors, age, or health conditions, and these changes may sometimes affect our eyesight. Blurred or fuzzy vision can affect different parts of your field of vision and may appear as an out of focus camera or like a thin film covering the eye, causing your eyesight to appear cloudy.  

Depending on the cause of your vision changes, it can affect your full eyesight, or just parts of it. This can either affect the central or peripheral vision in one or both eyes. 

Blurry central vision 

If your central vision is blurred or out of focus, it can affect your ability to read or drive safely.  

Losing focus in our central eyesight is typically caused by an injury or retinal or macula diseases, as the latter is part of the eye responsible for central vision. 

Blurry vision in one eye 

Some people may only notice a declining focus of either the left or right eye, when they are looking in the direction of the affected eye.  

The most common cause for this is a refractive error that is more severe in one eye than the other. This can be either short or long-sightedness, or an astigmatism. 

Blurry vision in one eye only can also be caused by a health condition or disorder affecting your brain or nervous system. Fuzzy vision in one eye may also occur after a traumatic injury to one side of your head.  

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What causes blurry vision? 

Whether your vision declines progressively, or your eyesight turns blurry overnight, there are various causes for loss of focus. Some of them are no reason for concern, while others require immediate action.  

We listed eight common causes for blurred vision below: 

Refractive error 

Refractive errors include long and short-sightedness, astigmatism and presbyopia.  

Short-sight causes far vision to appear blurry and long-sight affects the focus on close objects. Astigmatism causes vision to appear distorted and fuzzy and usually affects both distance and near tasks. Presbyopia is the age-related refractive error, that affects close vision, having an impact on everyday tasks like reading.  

Refractive error cannot be prevented from developing, but they are easily corrected through glasses or contact lenses with a prescription.  

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Eye strain  

Focusing on computer screens, your phone or a book with small font for too long, can cause your eyes to strain, which may result in blurred vision, especially in dark light settings. 

If you notice your vision turning fuzzy during long workdays, try taking several short breaks throughout the day to look at objects that are at least twenty feet away. 

Cataracts 

A cataract is a protein build-up in the lens of your eye, turning it cloudy. As the lens is responsible for the amount of light that enters your eye, the cataract can block the light from entering, which can lead to foggy or fuzzy vision, as if a thin veil is covering your eyes.  

Cataracts can either affect one or both eyes and tend to occur later in life. 

The cataract can be removed through surgery, which is a routine procedure for most ophthalmologists and usually restores your vision fully. 

Optic neuritis 

Optic neuritis is the inflammation of the optic nerve, which connects the eyes to the brain, and typically follows an autoimmune reaction.  

Blurred vision as a result of optic neuritis appears dim with reduced contrast and colours, particularly red, appear diluted or pale.   The condition usually only affects one eye.  

Optic neuritis tends to resolve over time, and once you have recovered, your eyesight should also return to normal.  

Regardless, optic neuritis needs further investigation, so should you experience any of the above symptoms, book an appointment with your optometrist as soon as possible. 

Detached retina 

The retina is a thin tissue that lines the back of the eyes and sends images through the optical nerve to the brain, which gives us our eyesight. If the retina moves away from its usual position, either caused by injury or age-related health conditions, it can impact sight profoundly. The usual warning symptoms of retinal detachments are flashes of light and a sudden increase in floaters in the affected eye.  

Retinal detachment should be treated immediately, otherwise it can lead to permanent vision loss. If you notice any symptoms, schedule an emergency appointment with your optometrist. 

Migraine 

Most people who suffer from migraines, will experience these accompanied by auras. An aura will cause vision disturbances or blurred vision in both eyes that typically start up to one hour before the headaches set in. Migraines can cause flickering lights or zig-zag lines to appear in your field of vision, which may increase in brightly lit environments such as rooms with fluorescent lights or bright TV screens.    

Typically, your vision will restore as the migraine disappears. Migraines cannot always be prevented, but if you suffer from migraines frequently, it is recommended to track these and find any triggers that might cause them. Talk with your doctor about possible medication, which you can take at the first signs of a migraine to reduce the symptoms. 

Diabetes 

If you are a diabetic, you will know how important it is to keep track of your glucose levels. High blood sugar can damage the blood vessels in your retina, which causes it to swell and leak and may result in the inability to see with a clear focus and detect details in objects. This can occur in just one or both eyes.   

Most people will notice their vision improving as their blood sugar levels regulate.  

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Preventing blurry vision 

Not every cause for blurred vision is preventable, but some can be spotted early during eye exams, or the risks can be reduced through some lifestyle changes.  

Regular eye exams 

If you know that one of your family members has a genetic condition or one that can be inherited, inform your optometrist of this, so they can keep an eye out for any signs. This allows them to offer early treatment which may slow down the progression of diseases that could impact your eyesight. 

Adults are recommended to schedule eye exams every two years, but should you experience sudden changes in vision, you can always arrange an emergency appointment. 

Healthy diet and lifestyle 

A diet for good eye health should include fruits and vegetables, and omega-3 fatty acids that can be found in certain nuts and seeds, or fish such as salmon or mackerel. You should also steer clear of smoking and increased alcohol consumption. 

Wearing UV-protecting sunglasses when you are exposed to the sun will reduce the risks of sun damage to your eyes.  

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