What is LASIK?
LASIK (Laser In Situ Keratomileusis) is a laser eye surgery procedure that permanently reshapes the cornea to correct refractive errors — myopia (short-sightedness), hyperopia (long-sightedness), and astigmatism. During the procedure, a thin flap is created in the outer layer of the cornea, the underlying tissue is precisely reshaped with an excimer laser to correct the prescription, and the flap is repositioned. The result, for suitable patients, is clear vision without the need for glasses or contact lenses.
LASIK is one of the most commonly performed elective surgical procedures worldwide, with an excellent track record for safety and efficacy. However, not everyone is a suitable candidate, and a thorough pre-operative assessment is essential before any decision is made.
Who is the Ideal Candidate for LASIK?
You are likely to be a good candidate for LASIK if you meet the following criteria:
Age 21 or older, with a stable prescription for at least 12 months. Prescriptions that are still changing are not suitable for laser correction, as the result would not be lasting.
Adequate corneal thickness. LASIK involves removing a small amount of corneal tissue to reshape it. Patients with thin corneas may not have sufficient tissue for safe laser treatment. Corneal thickness is measured precisely at your assessment.
No corneal disease. Conditions such as keratoconus — a progressive thinning and bulging of the cornea — are a contraindication to LASIK. Corneal topography (mapping of the corneal shape) is performed at your assessment to screen for such conditions.
No significant dry eye disease. LASIK can temporarily worsen dry eye symptoms. Patients with pre-existing significant dry eye may not be suitable, or may need treatment to optimise tear film health before proceeding.
Healthy eyes overall. Other eye conditions, including cataract, glaucoma, amblyopia (lazy eye), or retinal disease, may affect your suitability.
Who is NOT Suitable for LASIK?
LASIK is not appropriate for everyone. You may not be suitable if your prescription is still changing, if you have keratoconus or other corneal abnormalities, if your corneas are too thin, or if you have significant dry eye disease. Patients with very high prescriptions may also find that laser surgery cannot fully correct their vision, or that the risk-benefit ratio does not favour laser treatment.
Certain occupations — particularly those involving direct contact sports or roles where a corneal flap could be displaced — may also influence the choice of procedure. In these cases, a flapless procedure such as PRK or SMILE may be more appropriate.
Alternatives to LASIK
If LASIK is not suitable for you, there are several excellent alternatives:
PRK (Photorefractive Keratectomy): A surface laser procedure that does not create a flap. Preferred for patients with thin corneas or certain occupational requirements. Recovery is longer (1–2 weeks) but long-term outcomes are comparable to LASIK.
SMILE (Small Incision Lenticule Extraction): A flapless laser procedure using a different laser platform to remove a small disc of corneal tissue. Good option for myopia and myopic astigmatism.
Phakic IOL (Implantable Collamer Lens — ICL): A lens is implanted inside the eye in front of the natural lens. Ideal for patients with high myopia or corneas unsuitable for laser surgery.
Refractive Lens Exchange (RLE): The natural lens is removed and replaced with a premium artificial lens — the same procedure as cataract surgery. Best suited to patients over 45 with presbyopia, or those with prescriptions outside the range of laser surgery.
The Assessment Process with Dr MacIntyre
At your initial consultation, Dr MacIntyre will perform a comprehensive refractive surgery assessment. This includes detailed corneal topography and tomography, corneal thickness measurement, dry eye evaluation, wavefront aberrometry, pupil size measurement, and a full dilated eye examination. Based on these findings, he will advise you on whether LASIK or an alternative procedure is appropriate.
A referral from your GP or optometrist is required to attend for a refractive surgery assessment. If you wear contact lenses, you will be asked to stop wearing them for a period before your assessment, as lenses can temporarily alter corneal shape and affect measurements.
Expected Outcomes
The large majority of suitable LASIK patients achieve 6/6 (20/20) vision or better after surgery. Most can drive and perform daily activities without glasses from the day after surgery. A small number of patients may require a laser enhancement procedure, and virtually all patients will eventually need reading glasses as presbyopia develops in their mid-40s — this is a natural ageing process unrelated to the surgery.