Lazy Eye (Amblyopia)

Overview

Lazy eye or amblyopia is poor vision that results from interruption of normal visual development during the sensitive period in childhood.

After the age of seven years, the development of the part of the brain that processes vision is almost complete. If the brain has not received clear images from the weak eye, it would be difficult to improve vision in that eye after brain development is complete. The eye is then said to be “amblyopic” or “lazy”.

Causes

• Short-sightedness (myopia), long-sightedness (hyperopia) and/or astigmatism
• Large differences in refractive power (myopia, hyperopia or astigmatism) between both eyes
• Squint (strabismus)
• Obstruction of vision by droopy eyelids, cataracts or other eye conditions

Symptoms

Blur vision despite correction with spectacles.

Risk Factors

Children with the above mentioned causes, if not picked up by family members / health practitioners early on, are at risk of developing amblyopia. This may not be amenable to treatment if detected late.

Prevention

Screening for the above causes.

When To Seek Help

Often, the lazy eye may not be detected especially if unilateral, as the other eye often has good vision and the child thus may not complain of difficulty seeing. Do seek help if the child complains of poor vision, is unable to function well in school, fails a school vision screening test or is noticed to have eyes which are not aligned (i.e. squint). If picked up during routine eye screening, these cases are usually referred to an eye specialist.

Treatment Options

Lazy Eye (Amblyopia) is treatable during the sensitive period of childhood. The limits of this period are still being defined but in most cases, the ages of seven to eight are taken as the onset of visual maturity.

The initial step would be to prescribe spectacles for refractive errors, treat the squint, or offer surgery for more serious cases of childhood cataracts or droopy eyelids. The child is monitored until there is no further vision improvement.

Amblyopia is subsequently treated by preventing the use of the better eye and enforcing the use of the amblyopic eye for substantial periods of time. Occlusion of the normal eye with an adhesive patch is the mainstay of treatment.

Success of treatment depends on the severity of the lazy eye, the age when treatment is started and compliance with prescribed treatment. In general, the earlier the lazy eye is detected, the better the outcome from treatment.

Where To Seek Treatment

The medical institutions within SingHealth that offer consultation and treatment for this condition include:

Singapore National Eye Centre
11 Third Hospital Avenue,
Singapore 168751

Tel: (65) 6227 7255 (Office Hours)
      (65) 6532 4865,  6532 8833 (After Office Hours)

Frequently Asked Questions

1. Can both eyes have lazy eye (amblyopia)?

Yes. When there is an equal or substantial amount of vision impairement (eg: due to high refractive error), both eyes may be amblyopic.

2. Are there any specific activities recommended while patching?

No, as long as the child is utilizing her eyes (i.e. not sleeping). However, watching TV or allowing a child’s favourite activity while patching may encourage compliance.

3. Is there an alternative to patching to treat the lazy eye?

Occasionally, to encourage compliance, the ophthalmologist may elect to penalize the good eye with eye drops or altering the glasses prescription of the good eye.

4. How long does amblyopia treatment last?

This may last from weeks to months or years, depending on the severity of the vision impairment, age of the child and compliance with treatment.