Exploring the Most Common Causes of Blurred Vision

causes of blurred vision

Blurred vision can come on you suddenly and for no apparent reason. While it may seem minor, blurry vision can make driving, reading, or watching TV challenging. It can significantly interfere with your day-to-day activities.

Many causes of blurred vision can range from benign to severe. It’s important to distinguish between temporary and a sign of something more serious.

Learn more about the most common causes of blurry vision below.

Refractive Errors

Refractive errors such as nearsightedness, farsightedness, and astigmatism are the leading causes of blurred vision. Nearsightedness, or myopia, is usually caused when the eye is too long, or the cornea is too curved, hindering light from properly focusing on the retina.

Farsightedness, or hyperopia, occurs when the eye is too short, or the cornea is too flat. This results in light not focusing correctly and creating a blurred image.

Astigmatism, when the eye is shaped like a football instead of a sphere, can cause images to appear stretched or blurred. Because all these refractive errors cause the image being viewed to enter the eye without properly focusing, blurred vision can often result.

Abrasions to the Cornea

Abrasions to the cornea can commonly cause blurred vision and other vision-related problems. The cornea is the transparent and outermost layer of the eye. Its smooth surface handles refracting and reflecting light.

Any abrasion to the cornea can result in blurred vision, as the layer’s refractive power is diminished, leading to a distorted image. In more severe cases, abrasion to the cornea can cause a blockage, resulting in vision loss.

Common causes of abrasion to the cornea may include contact lens-related injury or dirt and debris irritating the eye. If left untreated, the effects may be long-term and could even lead to infection.

Age-Related Macular Degeneration

Age-Related Macular Degeneration (AMD) is an eye disease affecting the retina’s macula, or central area. This results in blurred or distorted vision over time. The primary cause of AMD is aging, with the risk increasing.

Other factors such as smoking, family history, high blood pressure, and obesity can also contribute to an increased risk of AMD. It also includes a genetic predisposition in those with a family history of the disease.

The symptoms of AMD can include the following:

  • Difficulty in seeing without glasses
  • Difficulty in detecting small objects
  • Blurred central vision
  • Difficulty in recognizing faces

AMD treatments generally focus on slowing the progression of the disease and managing the symptoms, but there is no known cure.


Cataracts are a common cause of blurred vision. They are most frequently attributed to age-related changes or long-term exposure to UV rays. When the eye’s natural lens becomes cloudy, light is usually prevented from entering the full spectrum of colors. It makes everything look blurry.

Cataracts occur when proteins found in the eye’s lens break down, causing the lens to become cloudy. As cataracts progress, they become flatter, thicker, and less clear, leading to more severe blurred vision.

In some cases, cataracts can cause a complete loss of vision, and immediate medical treatment is usually recommended. Treatment options can include surgery. It is where surgeons break up the cataract and replace it with an artificial lens. 

Corneal Opacification, or Scarring

Corneal opacification or scarring is one of the primary causes of blurred vision. When the cornea becomes scarred, it can cause the tissues and structures of the eye to become clouded. This results in a decrease in visual clarity and sharpness.

The cornea is the eye’s transparent outer layer that allows light to be focused and distributed within the eye. If this layer becomes permanently scarred and thickened, it can impair vision.

Common causes of cornea opacification or scarring are eye injury and trauma. It also includes the following:

  • Chronic eye irritation
  • Impaired corneal tear production
  • Corneal and conjunctival infections
  • Dry eyes

Some systemic diseases and medications can also lead to corneal opacification and scarring. Treatment for the condition includes surgical intervention. The use of antibiotics, steroids and lubricating prescription eye drops, and vision rehabilitation can help. 

Infectious Retinitis

Infectious retinitis is a type of retinal inflammation that a bacterial, viral, or fungal infection in the eye has caused. Symptoms include decreased vision and typically reduced visual acuity.

Blurred vision is one of the standard features of this condition. You may experience blurry or shadows and severely impaired contrast sensitivity. The condition is known to cause a decrease in visual performance collectively.

You may further reduce visual acuity and contrast sensitivity due to a decrease in the contrast sensitivity of the retinal pigment epithelium caused by the formation of inflammatory exudates.

The causes of infectious retinitis vary and can include bacterial, viral, or fungal infections of the eye, trauma, or other ocular disorders. Treatment typically involves antibiotics, antivirals, and antifungals for inflammation and infection, depending on the condition’s cause. Early diagnosis and treatment of infectious retinitis are essential to prevent further damage to the eye.

Optic Neuritis

Optic neuritis is an inflammatory disorder of the optic nerve, which can cause blurred or lost vision. It usually affects only one eye. Other common symptoms include eye pain associated with eye movement, decreased color vision, and temporary blindness in the affected eye.

Optic neuritis is believed to be caused by an autoimmune reaction of the body’s immune system. It occurs when the body’s antibodies mistakenly attack and damage the optic nerve due to a viral infection or an autoimmune disorder such as multiple sclerosis.

Optic neuritis can occur as a complication of multiple sclerosis, or it can be the first manifestation of the disorder. Other causes of blurred vision optic neuritis include injury to the eye or toxic substances, such as alcohol. In some cases, the exact cause may remain unknown.

Explore the Causes of Blurred Vision

Causes of blurred vision can be from various factors, such as age, improper use of glasses, or eye diseases. You must speak with your healthcare provider to identify the root cause of your blurred vision and manage your symptoms and treatment.

Remember, your vision is essential, and protecting it should be a priority. Make an appointment with your optometrist today. 

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