Blurred Vision
Blurred vision, or blurry vision, is a condition where eyesight is unclear, decreased in sharpness, hazy images, or loss of image details. Blurred vision may occur in one eye or both and may develop gradually or suddenly. Blurred vision is one of the most common eye symptoms, which can range from mild and harmless to life-threatening serious diseases. Typically, clear vision results from the coordinated functions of multiple eye structures, including the cornea, lens, vitreous humor, retina, optic nerve, and brain; blurred vision occurs when any of these structures are defective.
What causes blurred vision?
Common causes of blurred vision are as follows:
1. Eye-related causes (most common)
1.1 Refractive errors include myopia (nearsightedness) and hyperopia (farsightedness), which occur when light does not focus on the retina, and astigmatism, which occurs from uneven cornea curvature or lens in different axes (vertical/horizontal), creating two focal points on the retina instead of one, resulting in blurred vision.
1.2 Cornea and ocular surface diseases, such as dry eyes, keratitis, corneal ulcer, corneal edema, or corneal degeneration, cause the corneal surface to be uneven and opaque, reducing light entering the eye.
1.3 Lens disorders, such as cataracts, occur when the eye lens becomes cloudy due to aging or other factors, obstructing light transmission to the retina and resulting in low vision, light scattering, or washed-out colors.
1.4 Vitreous and retinal diseases include vitreous degeneration, diabetic retinopathy, age-related macular degeneration, retinal tears, retinal detachments, retinal artery occlusion, posterior uveitis, and infectious retinitis.
1.5 Glaucoma is a disease that damages the optic nerve and gradually reduces the visual field. Patients are frequently unaware of this in the early stages, and if left untreated, it can lead to permanent blindness.
2. Optic nerve and neurological causes
Although less common than eye-related causes, they are significant because they can be caused by certain serious conditions, including:
2.2 Stroke
2.3 Brain tumors or lesions compressing the optic nerve
3. Other diseases and conditions
3.1 Eye injuries, foreign bodies, chemical eye injury, bleeding in the eye, or globe rupture
3.2 Migraine with aura
3.3 High or low blood sugar levels
3.4 Abnormally high blood pressure, which can cause hypertensive retinopathy, artery narrowing, retinal hemorrhage, and optic disc swelling.
What are the symptoms of blurred vision?
Individuals experiencing blurred vision may have different symptoms, as follows:
- Seeing blurry images as if fog were obscuring vision.
- Difficulty seeing details, text appears blurry, seeing dark shadows
- Squinting or straining to see
- Seeing scattered light or excessively bright light
- Seeing double vision
Some people may also experience eye pain, pink eye, light sensitivity, headache, or dizziness. The symptoms' characteristics and duration play an important role for ophthalmologists in determining the cause of the disease.
Blurred vision requires immediate medical attention
Blurred vision that may indicate a medical emergency and necessitate immediate medical attention for diagnosis, as follows:
- Severe reduction of vision, sudden loss of vision
- Blurred vision in only one eye
- Blurred vision associated with severe eye pain or nausea
- Flashes of light, floaters, or a curtain-like shadow
- Loss of part of the visual field
- Facial drooping, drooping mouth corners, limb weakness, or slurred speech
These symptoms could indicate serious medical conditions, such as acute angle-closure glaucoma, retinal artery occlusion, or stroke, which require a prompt diagnosis and intervention as soon as possible.
How is blurred vision diagnosed?
The ophthalmologist will diagnose blurred vision by taking a medical history, inquiring about the duration of the symptoms, the symptom characteristics, any underlying diseases, and medications, followed by a detailed eye examination and additional exams at the doctor's discretion, as follows:
- Visual acuity testing
- Refraction (glasses prescription)
- Intraocular pressure measurement (Tonometry)
- Slit-lamp examination
- Fundus (retinal) examination
Additional examinations may include retinal imaging, OCT (optical coherence tomography), visual field testing, or brain MRI if needed.
How is blurred vision treated?
The ophthalmologist will determine treatment options for blurred vision based on the diagnostic result, as follows:
How to prevent blurred vision?
Blurred vision is preventable using the following eye care tips:
- Take regular eye exams at least once a year, especially if you're over 40 or have underlying conditions like diabetes, high blood pressure, or a family history of glaucoma.
- Rest your eyes from prolonged screen use. Use eye drops when experiencing dry eyes.
- Wear sunglasses to protect against UV radiation and reduce the risk of pterygium, cataracts, and macular degeneration.
- Wear safety glasses to protect your eyes while doing handyman work or mowing the lawn.
- Avoid areas with dense, heavy dust and fumes
- Manage underlying medical conditions appropriately.
- Do not self-medicate with eyedrops containing steroids.
Blurred vision is curable; shouldn’t prolong seeing a doctor
Blurred vision is the most common symptom of vision conditions. Abnormalities in various parts of the eye, including the cornea, retina, or optic nerve, as well as refractive errors, eye diseases, and chronic diseases, can cause blurred vision. I can be a warning symptom of a serious medical condition that requires immediate attention. Without timely treatment, it can lead to vision loss, disability, reduced quality of life, and difficulties in daily life.
Blurred vision may be secondary to myriad factors. Early seeking of a doctor for a physical examination helps doctors in determining the cause and guiding appropriate treatment. Those who experience persistent blurred vision, sudden blurred vision, sudden loss of vision, eye trauma, or acute onset of difficulty speaking or moving should seek medical attention as soon as possible.
