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Lens and refraction · AI
Laser refractive surgery: LASIK and SMILE
Excimer · femtosecond · does not treat the fundus
Last reviewed: 2026-10-06 · 潘家健醫生
Key points
Laser refractive surgery reshapes the cornea to reduce spectacle dependence — it does not shorten the axis or remove high-myopia fundus risk.
Suitability needs thickness, topography, ocular surface and dilated exam — no brands here.
Sudden vision drop or sudden blindness: go to A&E now.
Red painful photophobia without sudden blindness / severe pain and vomiting: same-day assessment; highly myopic eyes still need regular dilated exams after surgery.
Laser changes corneal shape so light focuses on the retina. It does not shorten the eye or remove the fundus risks of high myopia. Suitability needs thickness, topography, the ocular surface and a dilated exam. Platform brand names are not listed.
LASIK
A flap (usually femtosecond)
Excimer ablation of the stroma
The flap is replaced, usually without a suture
SMILE
A femtosecond lenticule is cut inside the stroma
It is removed through a small incision
Enhancement, if needed, often differs from lifting a LASIK flap
Night halos; under- or over-correction; rare ectasia
LASIK flap slip or epithelial ingrowth; SMILE lenticule remnants or suction loss
Presbyopia is not restored — monovision may be discussed after forty
Red, painful, photophobic vision: if vision drops suddenly or you go blind, go to A&E now. Red pain and light sensitivity without sudden blindness or vomiting: same-day ophthalmic assessment. Do not treat this as ordinary dry eye with over-the-counter drops. High myopes still need dilated fundus follow-up. No promise of “never glasses again”.
Video source: Hong Kong Ophthalmological Society (HKOS) “Eyes Decoded” YouTube (public education)
This site is not affiliated with, and is not the same organisation as, the Hong Kong Ophthalmological Society (HKOS).
This is general medical information, not a diagnosis, and cannot replace an in-person consultation with a registered ophthalmologist, refraction, or a dilated fundus exam. It is not advice to use any medicine or undergo any procedure. Medicines (including off-label use), laser or surgery must be decided by a registered doctor after examination, according to indications and Hong Kong registration. Figures from the literature are published averages, not any clinic’s results. This site does not book, prescribe or refer. Do not change treatment on your own.
