Refractive error (Myopia - Hyperopia - Astigmatism)
A refractive error occurs when light entering the eye is not focused at a precise point coinciding with the central retina.
Read article ↗WHAT YOU NEED TO KNOW
- FemtoLASIK and PRK are laser refractive surgery techniques.
- Preparation and recovery differ between the two techniques.
- Tests and clinical assessment determine whether surgery is appropriate.
Excimer laser surgery is usually used to correct refractive errors, improving visual independence and performance without glasses. It involves selective laser vaporisation of corneal tissue following a treatment pattern designed to correct the visual system's refractive error.
This procedure can correct short-sightedness, astigmatism and long-sightedness.
LASIK and PRK are the most widely used corneal refractive surgery techniques. Both have excellent efficacy and safety profiles when used in eligible cases after a thorough preoperative assessment.
FemtoLASIK and PRK: see the differences
Explore the two techniques side by side or select one. You can play, pause and move through the steps.
Corneal refractive surgery also offers an opportunity to correct other aberrations of the visual system, occasionally improving visual acuity compared with the best preoperative optical correction.
PATIENT GUIDE
LASIK care guide
Preparation, recovery and warning signs. This guide is specific to LASIK; PRK instructions are provided individually.
This information does not replace an individual medical assessment. Follow the advice of the team looking after you.
Before deciding, discuss these points at your appointment
- Indication
- What is the purpose of the procedure in my case?
- Alternatives
- What other options may be appropriate for my eyes?
- Recovery
- What care and follow-up will I need?
- Benefits and limitations
- What result can I expect, and what risks should I consider?
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Read the leaflet with adjustable text and print in larger typeDr. Nuno Lopes · Patient information
Editorial presentation updated on 27 October 2026. Your team's individual instructions take priority.
