Many parents find it hard to tell whether their child has strabismus or lazy eye. Let’s sort it out: what do the two have in common? Can they be treated the same way? Could they be misdiagnosed or mistreated? Does strabismus cause lazy eye, or does lazy eye cause strabismus?
Amblyopia, also called lazy eye, is exactly what the name suggests: the eye does move, but it is lazy and less agile than the other eye. The pupil stays in the centre, so there is no visible squint. In a vision screening it is clear that the two eyes move at different speeds, mainly because the eye muscles are underdeveloped and weak. The eye also cannot communicate well with the brain, which gradually learns to ignore its visual information. The child then sees with one eye only, loses 3D (stereo) vision and can no longer judge distances properly.
At present, lazy eye cannot be improved with corrective lenses, medication or surgery. Physical therapy works better, and optic-nerve physical therapy is popular across ASEAN – especially IONSPEC medical eyewear, which is widely trusted by patients in the region, can be used at any age and shows very encouraging clinical results. Lazy eye does not heal on its own; it becomes lazier and lazier until the eye stops moving altogether and loses its function. Lazy eye can also be caused by strabismus: because the brain cannot process two different images at once, it ignores the squinting eye, which gradually becomes lazy too – leading to both strabismus and lazy eye.
Strabismus is clearly visible: the eye may turn inwards, outwards, upwards or downwards, and in every case the eye’s movement is impaired. There is also pseudo-strabismus, where pupils set too close together or too far apart make the eyes look crossed. Like lazy eye, strabismus usually affects one eye, although in our many years of clinical work we have often met patients with both eyes affected. Strabismus confuses the brain with double images: when reading, children easily skip lines, see words overlap or blur, cannot focus for long, and suffer from sore eyes, sensitivity to light and quick eye fatigue. Clinical experience shows that long-sighted children are more likely to develop an inward squint. Strabismus most often appears around the age of 5 and only stabilises after 6-7, so parents should watch closely before school age – we recommend a vision function check every six months. With advances in medical technology, today’s parents need not worry too much: many former medical blind spots are gradually being overcome by technology, and problems medicine could not solve before can now be solved. The future will certainly be better – we hope parents will embrace new technology and make the wisest choice for their children.