Laser Eye Surgery Suitability
Laser eye surgery can transform vision for most people who wear glasses or contact lenses, but individual assessment is essential. At Blue Fin Vision®, consultant-led screening ensures the right procedure is recommended for your eyes, lifestyle and visual goals, or an alternative treatment if laser surgery is not suitable.
Am I Suitable for Laser Eye Surgery?
Approximately 85% of people are suitable for some form of laser eye surgery. If you meet the following criteria, you are highly likely to be a candidate for treatment, either with a laser procedure or possibly an implantable lens:
- Age 21 or over (22 or over for SMILE)
- Stable prescription for at least 12 months (no significant change in distance vision)
- Good corrected vision in each eye when wearing glasses or contact lenses
- Healthy eyes without significant disease or abnormality
- Good general health without conditions that impair healing
Your suitability will be confirmed through a comprehensive evaluation by our consultants at Blue Fin Vision®, ensuring the best possible outcome for your vision.
Prescription Ranges for Laser Eye Surgery
Each laser procedure has specific prescription limits. You are likely suitable if your glasses prescription falls within the following ranges:
Procedure | Myopia | Hyperopia | Astigmatism |
|---|---|---|---|
LASIK | Up to -10.00D | Up to +4.00D | Up to 6.00D |
PRK/LASEK | Up to -8.00D | Up to +4.00D | Up to 6.00D |
SMILE | -1.00D to -10.00D | Not available | Up to 3.00D |
PresbyMAX® | Variable | Variable | Variable |
PRESBYOND® | Variable | Variable | Variable |
Higher prescriptions may still be treatable depending on corneal thickness and other factors. Prescriptions outside these ranges may be better suited to implantable contact lenses (ICL) or refractive lens exchange.
Factors That Make Someone Highly Suitable
The ideal candidates for laser eye surgery share these characteristics:
- Stable prescription: No significant change (less than 0.5D) in the past 12 months. This ensures the correction will remain accurate long-term.
- Adequate corneal thickness: Sufficient tissue to safely remove the required amount during treatment. Thicker corneas provide more options.
- Normal corneal shape: Regular topography without signs of keratoconus or other irregularities.
- Healthy ocular surface: No severe dry eye, active infection or inflammation.
- Realistic expectations: Understanding that laser surgery aims to reduce or eliminate dependence on glasses, though reading glasses may still be needed after age 45.
- Good general health: No conditions that impair healing or increase infection risk.
These patients typically achieve excellent outcomes with high satisfaction rates.
Which Procedure is Right for Me?
Choosing the right laser procedure depends on your prescription, corneal characteristics, lifestyle and visual goals. Here is a guide to help match patients with the most suitable technique:
LASIK
Best for: Most patients seeking rapid visual recovery with minimal discomfort.
Ideal candidates:
- Myopia up to -10.00D, hyperopia up to +4.00D, astigmatism up to 6.00D
- Adequate corneal thickness (typically 500 microns or more)
- Normal corneal topography
- Office-based or sedentary lifestyle
- Those who want fastest possible recovery (vision often clear within hours)
May not be suitable if:
- Corneas are too thin
- High risk of eye trauma (contact sports, military, police)
- Severe pre-existing dry eye
- Abnormal corneal shape
PRK and LASEK (Including No-Touch TransPRK)
Best for: Patients with thinner corneas, active lifestyles or those at higher risk of eye trauma.
Ideal candidates:
- Myopia up to -8.00D, hyperopia up to +4.00D, astigmatism up to 6.00D
- Thin corneas unsuitable for LASIK or SMILE
- Contact sports participants, military personnel, police officers
- Those who prefer avoiding flap creation
- Previous LASIK patients needing enhancement
May not be suitable if:
- Cannot tolerate 3–5 days of discomfort during epithelial healing
- Need rapid visual recovery for work commitments
- Very high prescriptions (increased haze risk)
SMILE
Best for: Patients with myopia who want a flapless procedure with rapid recovery and reduced dry eye risk.
Ideal candidates:
- Myopia -1.00D to -10.00D with astigmatism up to 3.00D
- Age 22 or over
- Stable prescription for at least 12 months
- Those concerned about dry eye symptoms
- Active lifestyles where flap displacement is a concern
- Healthy corneas with adequate thickness
May not be suitable if:
- Long-sighted (hyperopia) – SMILE does not treat this
- Require presbyopia correction
- Very thin corneas
- Previous corneal surgery
PresbyMAX®
Best for: Patients aged 45 and above who want to reduce dependence on reading glasses while also correcting distance vision.
Ideal candidates:
- Age 45 and above experiencing presbyopia (difficulty with near vision)
- Presbyopia combined with myopia, hyperopia or astigmatism
- Those who have previously undergone laser eye surgery for distance vision and now need near vision correction
- Patients who have had cataract surgery but still require reading glasses
- Realistic expectations about multifocal vision
May not be suitable if:
- Require perfect vision at all distances without compromise
- Sensitive to visual disturbances such as halos
- Unable to adapt to multifocal corneal zones
PRESBYOND®
Best for: Patients aged 40–60 seeking natural blended vision at all distances with excellent binocular function.
Ideal candidates:
- Age 40–60 experiencing presbyopia
- Frustrated by reading glasses or varifocals
- Stable prescription for at least 12 months
- Healthy eyes without significant pathology
- Those who pass the pre-operative contact lens trial simulating blended vision
- Realistic expectations about neuroadaptation period
May not be suitable if:
- Unable to tolerate monovision in contact lens trial
- Require perfect distance vision in both eyes (e.g. professional drivers)
- Sensitive to night vision disturbances
Who May Not Be Suitable for Laser Eye Surgery?
Certain factors may make laser eye surgery inadvisable or require alternative approaches. Your consultant will assess these during your evaluation.
Age-Related Factors
- Under 18 years: The eye is still developing and prescriptions are typically unstable.
- Under 21–22 years: Some procedures (particularly SMILE) require patients to be at least 22. Younger patients may have unstable prescriptions.
- Presbyopia onset (mid-40s onwards): Standard laser procedures correct distance vision but will not prevent the need for reading glasses. PresbyMAX® or PRESBYOND® may be appropriate alternatives.
Prescription Instability
A stable prescription is essential for accurate treatment planning. Your prescription should not have changed significantly (less than 0.5D) for at least 12 months before surgery. Those in their early 20s may still experience prescription changes and should wait until stable.
Corneal Factors
- Thin corneas: Insufficient tissue to safely perform LASIK or SMILE. PRK may be an alternative, or implantable contact lenses (ICL) for very thin corneas.
- Irregular corneas: Abnormal topography, early keratoconus or forme fruste keratoconus increase ectasia risk. These patients are typically not offered LASIK or SMILE.
- Keratoconus: A progressive corneal condition that contraindicates laser eye surgery. Corneal cross-linking may be offered instead.
- Corneal scarring: Significant scarring involving the central visual axis may affect outcomes.
- Corneal dystrophy: Certain inherited corneal conditions may preclude treatment.
Eye Health Conditions
Several eye conditions may affect suitability:
- Glaucoma: Increased eye pressure or optic nerve damage may contraindicate treatment.
- Cataracts: Lens opacity requires cataract surgery rather than corneal laser treatment.
- Severe dry eyes: Significant dry eye disease should be treated and stabilised before considering laser surgery.
- Macular degeneration: Retinal conditions affecting central vision.
- Diabetic retinopathy: Active retinal disease from diabetes.
- Herpes eye infection (keratitis): History of herpes simplex keratitis increases risk of reactivation.
- Iritis or uveitis: Active inflammation inside the eye.
- Optic nerve damage: Pre-existing damage affecting visual potential.
General Health Conditions
Certain systemic conditions may affect healing or increase complication risk:
- Autoimmune conditions: Conditions like rheumatoid arthritis, lupus or Sjögren’s syndrome can impair healing and increase dry eye risk.
- Collagen vascular disease or Crohn’s disease: May affect wound healing.
- Ehlers-Danlos syndrome: Causes hyper-elasticity affecting corneal tissue.
- Marfan syndrome: Another connective tissue disorder where laser eye surgery is best avoided.
- Keloid scarring tendency: Conditions that inhibit normal healing may result in corneal haziness.
- Uncontrolled diabetes: Can affect healing and increase infection risk. Well-controlled diabetes is not necessarily a contraindication.
- Immunosuppression: Medications or conditions that impair immune function increase infection risk.
Temporary Factors
Some factors temporarily delay suitability rather than permanently exclude:
- Pregnancy or breastfeeding: Hormonal changes can affect prescription stability. Wait at least 3 months after cessation of breastfeeding before considering laser eye surgery.
- Active eye infection or inflammation: Treatment should wait until the eye is healthy.
- Recent prescription change: Wait until stable for at least 12 months.
- Contact lens wear: Soft lenses should be removed 1–2 weeks before assessment; rigid gas permeable lenses 3–4 weeks before, to allow accurate corneal measurements.
Other Factors
- Unrealistic expectations: Patients expecting guaranteed perfect vision in all conditions without any possibility of needing glasses may be disappointed.
- Occupational requirements: Some professions have specific visual standards. Check requirements before proceeding.
- Significant squint (strabismus): May affect binocular vision outcomes.
- Blindness or severe vision loss in one eye: Treating the only seeing eye carries higher risk considerations.
What If I Am Not Suitable for Laser Eye Surgery?
If laser eye surgery is not appropriate for your eyes, Blue Fin Vision® offers excellent alternatives:
Implantable Contact Lenses (ICL)
Ideal for patients with:
- Very high prescriptions outside laser treatment range
- Thin corneas unsuitable for laser surgery
- Dry eyes that may worsen with laser treatment
- Keratoconus or irregular corneas (in selected cases)
ICL involves placing a biocompatible lens inside the eye, in front of the natural lens. It is reversible and preserves corneal tissue.
Refractive Lens Exchange (RLE)
Ideal for patients with:
- Age 50 and above
- Early cataracts developing
- Very high prescriptions
- Desire to address presbyopia and distance vision simultaneously
RLE involves replacing the natural lens with a premium intraocular lens, like cataract surgery but performed before cataracts develop significantly.
Corneal Cross-Linking
For patients with keratoconus or corneal ectasia, cross-linking strengthens the cornea and may stabilise vision, potentially allowing future vision correction options.
Your consultant will discuss all suitable alternatives if laser eye surgery is not recommended.
The Assessment Process at Blue Fin Vision®
Your suitability journey begins with a comprehensive consultation including:
Detailed History
We review your prescription history, previous eye problems, general health, medications, lifestyle and visual goals. Understanding your priorities helps us recommend the right procedure.
Refraction and Visual Acuity
Precise measurement of your current prescription and best-corrected vision. This determines the treatment parameters and confirms you can achieve good vision with correction.
Corneal Assessment
- Topography: Maps the curvature of the front corneal surface, detecting irregular astigmatism or early keratoconus.
- Tomography: Creates a 3D map of the entire cornea, including the back surface, for comprehensive assessment.
- Pachymetry: Measures corneal thickness at multiple points, ensuring adequate tissue for safe treatment.
Ocular Surface Evaluation
Assessment of tear film quality, dry eye signs and overall ocular surface health. Pre-existing dry eye can be optimised before surgery to improve outcomes.
Pupil Size Measurement
Large pupils in dim light may increase the risk of night vision disturbances. This helps guide procedure selection and optical zone planning.
Retinal and Optic Nerve Examination
Dilated examination ensures the retina and optic nerve are healthy, confirming you are likely to achieve good visual outcomes.
Treatment Discussion
Based on all findings, your consultant discusses:
- Which procedure(s) you are suitable for
- The recommended option and why
- Expected outcomes and limitations
- Risks specific to your situation
- Alternative treatments if laser is not ideal
Realistic Expectations
We ensure you understand:
- Likely visual outcomes for your prescription
- The possibility of needing enhancement
- Reading glasses may still be needed after age 45 (unless presbyopia correction is chosen)
- Rare but possible complications
Special Considerations
Athletes and Active Lifestyles
If you participate in contact sports, martial arts, or activities with risk of eye trauma, surface procedures (PRK/LASEK) or SMILE may be preferable to LASIK, as there is no flap that could be dislodged.
Military and Emergency Services Personnel
Certain professions have specific visual requirements. PRK and SMILE are often preferred over LASIK for military personnel due to greater corneal stability. Check your occupational requirements before proceeding.
Previous Eye Surgery
If you have had previous laser eye surgery, enhancement may be possible depending on corneal thickness and time since the original procedure. Previous LASIK patients can often have the flap relifted for enhancement or undergo PRK on top.
Contact Lens Wearers
Contact lenses temporarily alter corneal shape. To ensure accurate measurements:
- Soft lenses: Remove 1–2 weeks before assessment
- Toric soft lenses: Remove 2 weeks before assessment
- Rigid gas permeable (RGP) lenses: Remove 3–4 weeks before assessment
Your consultant will advise on the appropriate timeline.
Quick Suitability Checklist
Use this checklist to get an initial indication of your likely suitability:
You are likely suitable if you:
- Are aged 21 or over (22 for SMILE)
- Have had a stable prescription for at least 12 months
- Can see well with glasses or contact lenses
- Have healthy eyes without significant disease
- Are in good general health
- Have realistic expectations about outcomes
You may need further assessment or alternatives if you:
- Have very thin corneas
- Have irregular corneal shape or keratoconus
- Have severe dry eyes
- Are pregnant or breastfeeding
- Have autoimmune conditions
- Have glaucoma, cataracts or retinal disease
- Have an unstable prescription
Even if you tick some items in the second list, you may still be suitable for certain procedures or alternative treatments. Only a comprehensive assessment can determine your options.
What Sets Blue Fin Vision® Apart
Our consultant-led assessment ensures:
- Expert evaluation by your named surgeon using advanced wavefront-guided diagnostics for precision treatment planning
- Zeiss VisuMax femtosecond laser technology offering superior cutting precision and faster recovery
- Full range of procedures including tailored to your corneal characteristics
- Honest discussion of risks, benefits and realistic outcomes based on your individual suitability
- Support for complex cases, including thin corneas, high prescriptions or previous unsuccessful consultations elsewhere
- Free consultations for laser eye surgery, reflecting confidence in our assessment process
- UK-regulated care with CQC-regulated facilities and NOD-audited outcomes
- Multiple convenient locations across London, Hertfordshire and Essex for easy access
Take the First Step
Unsure if laser eye surgery is right for you? Blue Fin Vision® offers FREE consultations for laser eye surgery, allowing you to discover your options without obligation.
Our expert team will assess your eyes, discuss your visual goals, and recommend the most suitable treatment, whether that is LASIK, PRK, LASEK, SMILE, PresbyMAX®, PRESBYOND® or an alternative such as ICL.
Book your FREE consultation today at our London, Chelmsford or Hatfield clinic and discover how laser eye surgery can transform your vision and your life.
