Causes of blurred vision typically fall into two main categories.
The misfocusing of light in the eye is the most common cause of blurred vision. This is usually due to the eye being slightly too long, too short or has an irregular shape. Our optometrists can diagnose this and help you see clear again with prescription glasses or contact lenses.
To see your best your eyes need to be healthy. Cataracts, glaucoma, macular degeneration and dry eye are some common conditions that cause blurred or reduced vision. Some serious eye conditions, if not detected and treated promptly, can cause permanent loss of vision.
Eye Focusing Issue
Refractive errors arise from the misfocusing of light in the eye. Below are the four most common causes of blurred vision - all of these can be corrected by our optometrist with prescription glasses or contact lenses, so you can see clearly again.
also called "short-sightedness" or "near-sightedness"
Myopia is commonly caused by the eye growing slightly too long, so light is mis-focused in front of the retina. The longer the eyeball, the greater the degree of myopia. Myopia typically begins in childhood and worsens in adolescence as the eye grows.
A person with myopia can see close objects clearly, while objects in the distance will appear blurry. A child with myopia may find it hard to see the board at school, while an adult may have trouble seeing signs when driving, or recognising faces from a distance.
Myopia development is influenced by both genetics and environmental factors. Having one or both parents with myopia, and spending a lot of time indoors, reading too close, school work, tablet and computer use all increase the risk of developing myopia.
Myopia is the most common vision problem in children and young adults
And it poses the greatest risks for the long-term health of the eyes.
also called "far-sightedness" or "long-sightedness"
Hyperopia occurs when the eye is too short. Low amounts of hyperopia is common in kids and usually isn't a problem as children's eyes can adjust focus to compensate. However, some children may experience discomfort and headaches from the constant focusing.
A far-sighted person has better vision in the distance than at near. They need to work their eyes harder to focus up close, and to maintain that focus. Over time this causes the eye muscles to strain, often leading to headaches, sore eyes and tiredness.
Symptoms of hyperopia may be relieved by glasses, eye exercises or taking more breaks from close-up work. In children, a high degree of uncorrected hyperopia, particularly if only in one eye, can cause eye mis-aligment (strabismus) and lazy eye (amblyopia).
sometimes also called "cylinder" or "football shaped eye"
Astigmatism is an irregularity or imperfection of the front surface of the eye. Instead of being perfectly round, the eye is oval shaped. Astigmatism is very common - around half of people with glasses have some amount of astigmatism in their glasses prescription.
People with astigmatism can have blurred vision in the distance as well as close-up. Some describe the blur as being like an overlapping shadow, which is very uncomfortable for the visual system. Astigmatism, when not corrected properly, can often cause headaches and eyestrain.
Astigmatism can occur alone or in combination with nearsightedness and farsightedness. Most types and degrees of astigmatism can be corrected fully by glasses and contact lenses. Contact lenses for astigmatism are often referred to as 'toric lenses'.
the loss of focusing flexibility with age
As we age, our eyes gradually lose flexibility like the rest of our bodies. The lens inside our eyes becomes less elastic and less able to quickly adjust focus. Changing our focus from distance to near, and back, becomes slower. Reading and detailed close-up work becomes increasingly harder.
People with normal distance vision will start to hold their book further away to read more comfortably. Those who are naturally near-sighted
may find close reading easier without their long-distance glasses. And farsighted people will find reading at near very difficult and uncomfortable.
Presbyopia tends to occur at around age 45, earlier for some and later for others. Prescription reading glasses will help. Those already wearing glasses for distance, multifocal or bifocal lenses may be the best solution to correct both the long and short distances in a single pair of glasses.
other eye conditions
Eye Health Conditions
It's more than vision
Below are common eye health conditions and diseases which can cause blurred vision, and in some cases lead to severe loss of vision.
Our optometrists are trained to detect, diagnose and manage these eye conditions, as well as other eye health issues. Where necessary, we can also provide referrals to ophthalmologists (eye specialists) for further examination and management.
A cataract is an opacity or yellowing of the eye's natural crystalline lens. Most often occurring with age, cataracts usually develop slowly, gradually making vision more blurry, like looking through a foggy window, and also causes significant glare.
Glaucoma occurs when the optic nerve is damaged by a build up of pressure inside the eye. Over time it causes irreversible loss of peripheral (side) vision. Glaucoma runs in families and a more aggressive type is more common in people of Asian descent.
Macular degeneration (AMD) is a progressive disease of a critical central area of the retina. It causes painless, permanent loss and distortion of central vision. In advanced cases it can affect a person's ability to drive, read, see fine detail and recognise faces.
Diabetes causes blood vessel changes throughout the body, and in the eye it can cause leaky new vessels, bleeding, vision loss and serious complications. An optometrist can sometimes detect diabetes before a patient is aware they have the condition.
Floaters are small protein fibres from the gel-like substance called the vitreous at the back of the eye. They appear as black or grey spots, strands or cobwebs. Large floaters can cause blurred vision. If new floaters occur with flashes of light, have your eyes checked immediately.
Retinal lesions can be serious and lead to permanent vision loss. Retinal detachment, where the retina peels away from the back of the eye, can occur with trauma or age, and people with higher degrees with short-sightedness are at much higher risk.
Eye infections are common, especially in kids. Bacterial conjunctivitis is particularly contagious. Contact lens wearers are also at higher risk of developing infections. Our optometrists are qualified to identify and diagnose these conditions.
Dry eye is a common, sometimes chronic condition, and can occur at any age. It may cause blurred vision that comes and goes. Other symptoms include irritation, redness, stinging or burning sensation, mucus around the eyes, itchy, tired or watery eyes.
A pterigium is a slow, benign growth of the eye's outer membrane onto the cornea, forming a triangular lump of tissue. In more advanced cases it can interfere with vision. It is common in Singapore and is associated with exposure to the sun and UV light.