Amblyopia, commonly known as “lazy eye,” is a developmental visual condition in which one eye doesn’t achieve normal visual acuity, even with corrective lenses. It usually begins in childhood when the brain and eye are still learning to work together. Although the condition often goes unnoticed because the stronger eye compensates, early detection and treatment are key to ensuring optimal vision development.
Amblyopia typically develops when the brain favors one eye over the other, leading to underuse of the affected eye. This can happen for several reasons:
- Strabismus: Misalignment of the eyes can force the brain to ignore the input from the deviating eye.
- Refractive errors: When there’s a significant difference in the prescription (anisometropia) between the two eyes, the brain may rely more on the eye with clearer vision.
- Visual deprivation: Conditions such as congenital cataracts or other obstructions that prevent clear vision during early childhood can result in amblyopia.
These factors disrupt normal visual development and cause the brain to ‘tune out’ signals from the affected eye.
Early detection is key. In many cases, amblyopia can be prevented from becoming a long-term issue if caught early. Routine eye examinations during infancy and early childhood can identify risk factors—like misalignment or significant differences in refractive error—before amblyopia becomes severe. Prompt treatment, such as corrective lenses or patching therapy, can help steer visual development in the right direction. However, if left undetected, amblyopia may become permanent.
Amblyopia is often subtle and may be noticed only during routine eye tests rather than from obvious signs. Some common symptoms include:
- Reduced vision in one eye compared to the other
- The affected eye may seem to wander or not align with the other eye
- Difficulty with depth perception or problems with tasks that require good binocular vision
Because children might not complain about vision issues, amblyopia is usually identified during regular check-ups rather than from self-reported symptoms.
The main aim of amblyopia treatment is to strengthen the weaker eye and improve overall vision by encouraging the brain to use both eyes. Treatment options include:
- Corrective lenses: Glasses or contact lenses help to correct refractive errors that may be contributing to amblyopia.
- Patching therapy: Covering the stronger eye with a patch forces the brain to rely on the weaker eye, which can improve its visual performance.
- Atropine drops: These are sometimes used in the stronger eye to blur its vision, encouraging the use of the amblyopic eye.
- Vision therapy: Structured exercises and activities can help improve visual skills and eye coordination.
Early detection increases the probability of successful treatment, and the lazy eye can ‘catch-up’ to the good eye. Late detection means a high chance that no improvement can made to the lazy eye and it will be permanently blurry.
When should I see an optical professional about amblyopia?
If you notice that your child is having difficulty with tasks that require clear vision—such as reading, recognising faces, or judging depth—or if you suspect that their eyes are not aligning properly, it’s important to have them examined by an optometrist or ophthalmologist.
It can be difficult to detect as it presents in young children and most people always have both eyes open. Therefore, it is important to make sure all children start their eye examinations from the age of 5 to make sure their eyesight is developing correctly, as the ability of the visual system to adapt declines with age.
