At Pure Sight Eye Surgeons, we investigate the cause of your blurred vision thoroughly, using a combination of clinical examination and advanced diagnostic imaging to determine whether it’s a straightforward refractive issue or something that needs closer attention.
Common Causes of Blurred Vision
Refractive errors
The most common cause of blurred vision is a refractive error, where the shape of the eye prevents light from focusing correctly on the retina. This includes myopia (short-sightedness), hyperopia (long-sightedness), astigmatism, and presbyopia (age-related difficulty with near vision). These are corrected with glasses, contact lenses, or refractive surgery.
Cataracts
As the natural lens inside the eye gradually clouds with age, vision becomes progressively blurred, hazy, or faded. Cataracts are one of the most common causes of gradually worsening vision in people over 60 and are treated with surgery.
Dry eye disease
An unstable or insufficient tear film can cause fluctuating blurred vision, particularly during reading, screen use, or in air-conditioned environments. Blinking often temporarily clears the blurriness. Dry eye is very common and can coexist with other conditions.
Glaucoma
While glaucoma typically affects peripheral vision first, advanced disease can blur central vision. Acute angle-closure glaucoma can cause sudden, severe blurred vision and is a medical emergency.
Macular degeneration
AMD causes blurring or distortion of central vision. Straight lines may appear wavy, and there may be a smudge or blank spot in the centre of your visual field.
Diabetic eye disease
Fluctuating blood sugar levels can cause temporary blurring as the lens inside the eye swells. Diabetic retinopathy and macular oedema can cause more persistent vision changes. If you have diabetes and notice blurred vision, it’s important to have your eyes checked.
Other causes
Blurred vision can also result from:
- Uveitis (inflammation inside the eye)
- Keratoconus (thinning and distortion of the cornea)
- Corneal disease or infection
- Retinal detachment (a medical emergency, often accompanied by flashes and floaters)
- Optic neuritis (inflammation of the optic nerve, sometimes associated with multiple sclerosis)
- Migraine (visual disturbances with or without headache)
- Medications, including antihistamines, antidepressants, oral contraceptives, and some blood pressure medications
- Damaged or poorly fitting contact lenses
When to Seek Urgent Assessment
Most causes of blurred vision are not emergencies, but some require urgent attention. Seek immediate assessment if you experience:
- Sudden loss of vision in one or both eyes
- Sudden onset of flashes of light or a significant increase in floaters
- A shadow or curtain appearing across your vision
- Severe eye pain with blurred vision, redness, or halos around lights
- Blurred vision following an eye injury
- Sudden blurred vision accompanied by headache, difficulty speaking, or weakness on one side of the body (which may indicate a stroke)
If you’re unsure whether your symptoms are urgent, call our rooms on 1300 DR CHIU (1300 37 2448) for advice.
Diagnosis
Your assessment at Pure Sight will be guided by your symptoms and history. It may include:
- Visual acuity testing — to measure how clearly you can see at distance and near
- Refraction — to determine whether a glasses prescription is needed or has changed
- Slit lamp examination — to inspect the front of the eye, including the cornea, iris, and lens
- Dilated retinal examination — drops widen the pupils so the retina, macula, and optic nerve can be examined in detail
- Intraocular pressure measurement — to check for glaucoma
- Corneal thickness measurement – to accurately adjust the pressure reading
- OCT imaging — to assess the retina and optic nerve in fine detail
- Visual field testing — if glaucoma or neurological causes are suspected
Frequently Asked Questions
Should I be worried about blurred vision?
Blurred vision that develops gradually and improves with glasses is usually straightforward. However, sudden blurred vision, blurriness in one eye only, or blurred vision accompanied by other symptoms like flashes, floaters, pain, or headache should be assessed promptly. When in doubt, it’s always better to have it checked.
Can screen time cause blurred vision?
Extended screen use can cause eye strain and temporary blurring, often related to reduced blinking and dry eye. This typically improves with breaks and dry eye treatment and doesn’t indicate permanent damage. However, if blurred vision persists after resting your eyes, you should have an assessment to rule out other causes.
Why is my vision blurry in the morning?
Morning blurriness can be caused by dry eyes (the tear film is less stable during sleep), mild corneal swelling that occurs overnight, or sleeping in a position that puts pressure on the eye. If it clears within a few minutes of waking, it’s usually not a concern. Persistent morning blurriness, particularly if it’s getting worse, is worth investigating.