Blurred vision

What is blurred vision and why does it happen?

If you are not seeing clearly, and rubbing your eyes isn’t helping, you might be experiencing blurred vision. Blurred vision occurs when you are unable to detect the fine details of the object you are looking at, regardless of its distance. Your eyes cannot process light signals sharply, and therefore you are unable to focus on objects clearly, making them appear hazy and blurred.

If you are experiencing blurred vision, it is advised to have your eyes examined. Your optometrist can determine whether to recommend prescription glasses or contact lenses.

You can get blurred vision in both eyes or just in one eye, depending on what other eye conditions you have. Patients who have presbyopia, myopia, hypermetropia and astigmatism are more likely to experience blurred vision.

People can underestimate the fact that blurry vision can be a direct effect of other medical conditions such as stroke or migraine. Taking certain medications can also result in blurred vision, along with other side effects, such as headaches, sensitivity to light, and red, irritated eyes.¹

Although blurred vision can be a result of refractive errors in the eye, it could have consequences for your eye health if left untreated. There might be other reasons for blurred vision and you may need to consider if it could be an eye disease or a neurological disorder.

Blurred vision, also known as cloudy vision, occurs when the eye views objects as though through a milky film or cloudy lens. This is a common symptom in the case of people with cataracts.²

Other factors causing blurry vision⁶

Myopia

People with myopia (near-sightedness), which can cause blurred vision when looking at objects in the distance, will usually squint their eyes to see those objects in the distance clearer. Myopia can then further strain their eyes and cause other symptoms, such as headaches.⁷,⁸

Hypermetropia

Hypermetropia, or hyperopia, most commonly known as farsightedness, is the opposite of myopia. Hypermetropia occurs when objects in the distance are usually seen clearly, but nearby objects are not. These nearby objects appear blurry, so the eye muscles will overcompensate, which can result in eye strain and eye fatigue when trying to focus on seeing the near object clearly.⁹

Astigmatism

With astigmatism, near and far distances can appear to be blurred. This is caused by a refractive error in the lens, which can be a result of an irregularly-shaped cornea. The eyes of people with astigmatism do absorb light rays, but those light rays do not land on the retina (the back of the eye), which results in blurry or distorted vision.¹⁰

Presbyopia

Presbyopia is an age-related eye condition. The blurred vision occurs, like with hypermetropia, when focusing on nearby objects. Due to the lens losing its elasticity, accommodation (the relaxation and tensing of the eye muscles, making them able to switch between distant view and nearby objects) becomes harder, making it difficult for you to read fine print, newspapers, or text on mobile and on computer screens. These symptoms tend to become more prevalent as you age.¹¹

Diabetic retinopathy

This is when people with type 1 or type 2 diabetes develop deterioration of the blood vessels in the back of the retina. When the blood vessels in the retina are severely damaged, the retina can weaken, resulting in failing to process light signals efficiently, which can cause blurred and distorted vision.¹²

Age-related macular degeneration

This disease is an age-related eye condition. Age-related macular degeneration occurs when the macula, at the centre of the retina, fails to focus on objects, causing blurred vision, or in rare cases, total vision loss.¹³

Eye allergies

Seasonal allergies can also affect our quality of vision, as they can irritate the corneal surface of the eye. When the cornea is inflamed due to exposure to external elements such as dust, pollen, or pollution, it can be hard to focus on objects clearly, resulting in temporary blurred vision.¹⁴

Your optometrist will then carry out the following examinations:¹⁵

A check of how clearly you can see letters on a chart from distance, alternately covering your right and left eye
Refraction tests
Examining your external ocular health
Examining your internal ocular health
Tonometry
Imaging of the eye, if required

How is blurred vision treated?

Depending on the cause, there can be various treatments. Some are listed below.

Glasses or contact lenses
Medicated and antibacterial eye drops
Laser surgeries such as LASIK
Certain medications to control blurred vision symptoms
Getting sufficient sleep
Avoiding reading fine print or text in dim light
Drinking plenty of water to hydrate and lubricate the eyes

Can blurred vision be prevented?

It cannot always be prevented. In some cases, blurred vision can be the result of age. In other cases, it cannot be prevented, but it can be treated. There are some measures you can take that might help:

Regular eye examinations, at least once every two years
Always wash your hands before putting in contact lenses
Always wear sunglasses when out in the sun
Consume a diet rich in healthy fats such as nuts and seeds, and antioxidants such as leafy vegetables. A high intake of vitamins A and C is also recommended.¹⁶

Medically reviewed by Peena Govind on September 29, 2022

Sources

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