Blurred vision is a condition in which your eyesight becomes unclear, out of focus, or less sharp than usual. It may be caused by refractive errors such as nearsightedness or astigmatism, eye infections, dry eye disease, cataracts, glaucoma, retinal disorders, or corneal conditions.
If blurred vision develops suddenly or is accompanied by flashes of light, a sudden increase in floaters, or a curtain-like shadow over your vision, seek immediate evaluation by an ophthalmologist.
What Is Blurred Vision?
Blurred vision refers to difficulty seeing objects clearly or sharply. It may feel as though your vision is out of focus, hazy, or as if you are looking through a dirty or fogged-up window.
Blurred vision can affect one or both eyes and may develop gradually or suddenly. It is not a disease itself but a symptom that may indicate various eye conditions.
What Causes Blurred Vision?
Below are seven common causes of blurred vision.
1. Nearsightedness, Farsightedness, or Astigmatism
Refractive errors are among the most common causes of blurred vision. These include:
- Myopia (nearsightedness)
- Hyperopia (farsightedness)
- Astigmatism
- Presbyopia (age-related farsightedness)
People with myopia usually have difficulty seeing distant objects clearly, while astigmatism can make vision appear blurry or distorted.
A comprehensive refraction test can determine the most appropriate vision correction.
2. Eye Infections
Eye infections, such as conjunctivitis, keratitis, or infections affecting other parts of the eye, can cause blurred vision.
Inflammation may disrupt the clarity of the eye’s surface, preventing light from being focused properly.
Common accompanying symptoms include:
- Red eyes
- Eye pain
- Excessive tearing
- Eye discharge
- Light sensitivity
- A foreign body sensation
Proper treatment depends on the underlying cause of the infection and is important to prevent vision-related complications.
3. Dry Eye Disease
Blurred vision that improves temporarily after blinking may be related to dry eye disease.
An unstable tear film can affect the quality of vision. In addition to blurred vision, dry eye disease may cause:
- A gritty sensation
- Burning or stinging
- Eye fatigue
- Red eyes
- Light sensitivity
- Excessive tearing
Research on dry eye disease has shown that symptoms may include fluctuating blurred vision, glare, visual changes after blinking, and eye fatigue.
4. Cataracts
Blurred vision that resembles looking through a foggy window may indicate cataracts.
A cataract develops when the eye’s natural lens becomes cloudy.
Other symptoms may include:
- Hazy or cloudy vision
- Increased sensitivity to bright light
- Difficulty seeing at night
- Halos around lights
- Colors appearing less vibrant
A comprehensive eye examination is necessary to confirm whether cataracts are causing the symptoms.
5. Glaucoma
Glaucoma is a group of eye diseases that damage the optic nerve.
Some types progress slowly without noticeable symptoms. However, acute glaucoma may develop suddenly and cause:
- Blurred vision
- Severe eye pain
- Red eyes
- Halos around lights
- Headache
- Nausea or vomiting
These symptoms require immediate medical attention.
6. Retinal Disorders
The retina is the light-sensitive tissue at the back of the eye that plays a critical role in vision.
Retinal disorders may cause blurred vision along with:
- Floaters
- Flashes of light
- Dark areas in the visual field
- A curtain-like shadow across the vision
A sudden increase in floaters, flashes of light, or a curtain-like shadow may indicate a retinal tear or retinal detachment and should be evaluated immediately.
One retinal condition that deserves special attention is diabetic retinopathy, which occurs when diabetes damages the blood vessels of the retina.
In its early stages, diabetic retinopathy may not cause symptoms. As it progresses, patients may experience blurred vision, floaters, dark spots, and reduced visual acuity.
People with diabetes should undergo regular eye examinations according to their ophthalmologist’s recommendations.
7. Corneal Disorders
The cornea is the clear front surface of the eye that helps focus incoming light.
Infections, injuries, inflammation, or structural changes affecting the cornea can interfere with clear vision.
Symptoms may include:
- Blurred vision
- Red eyes
- Eye pain
- Watery eyes
- Light sensitivity
- A foreign body sensation
Red eyes accompanied by pain and blurred vision should be evaluated promptly.
Why Is My Vision Blurry Even Though I’m Wearing Glasses?
Blurred vision is not always caused by an outdated eyeglass prescription.
Although refractive errors are often corrected with glasses, other conditions—including infections, dry eye disease, cataracts, glaucoma, corneal disorders, and retinal diseases—may continue to cause blurred vision despite wearing corrective lenses.
Simply changing your glasses repeatedly may not solve the underlying problem.
Can Looking at Your Phone Too Long Cause Blurred Vision?
Extended use of digital devices may contribute to digital eye strain.
Common symptoms include:
- Eye fatigue
- Eye discomfort
- Headaches
- Temporary blurred vision
If blurred vision persists or continues to recur even after resting your eyes, an eye examination is recommended to determine the underlying cause.
When Should You See an Ophthalmologist Immediately?
Seek urgent medical attention if blurred vision:
- Develops suddenly
- Causes rapid vision loss
- Is accompanied by severe eye pain
- Occurs with red eyes
- Is associated with a sudden increase in floaters
- Is accompanied by flashes of light
- Causes a curtain-like shadow over your vision
Sudden changes in vision may indicate a serious eye condition that requires immediate treatment.
Can Blurred Vision Be Treated?
Whether blurred vision can improve depends on its underlying cause.
Refractive errors can often be corrected with glasses, contact lenses, or refractive procedures. Meanwhile, eye infections, dry eye disease, cataracts, glaucoma, corneal disorders, and retinal diseases each require different treatment approaches.
Identifying the underlying cause is the first step toward choosing the most appropriate treatment.
Don’t Assume Blurred Vision Is Always Caused by Nearsightedness
Although blurred vision is commonly caused by myopia or astigmatism, it may also result from eye infections, dry eye disease, cataracts, glaucoma, corneal disorders, or retinal diseases.
If your vision becomes increasingly blurry, does not improve, or begins to interfere with your daily activities, schedule a comprehensive eye examination to determine the cause.
Don’t ignore your eye health. Having a comprehensive eye examination every six months can help detect potential problems early. After all, prevention is always better than treatment.
FAQ About Blurred Vision
No. Blurred vision may also result from dry eye disease, cataracts, glaucoma, corneal disorders, diabetes-related eye disease, or retinal conditions.
Foggy vision may occur in several eye conditions. Cataracts are one possible cause, but a comprehensive eye examination is necessary to determine the exact reason.
Prolonged screen time may contribute to digital eye strain and temporary tear film instability, leading to temporary blurred vision.
It depends on the underlying cause. Some conditions can be corrected or successfully treated, while others require ongoing monitoring and specialized care.
Referensi:
World Health Organization. Blindness and Vision Impairment.
National Eye Institute. Eye Conditions and Diseases; Retinal Detachment.
Koh S. Mechanisms of Visual Disturbance in Dry Eye. Cornea. 2016.
Sheppard AL, Wolffsohn JS. Digital Eye Strain: Prevalence, Measurement and Amelioration. BMJ Open Ophthalmology. 2018.
Medically reviewed by: dr. Rahayu Widhyasti, Sp.M
