How Do I Know Which Vision Correction Procedure Is Right for Me? A Medical, Not Sales-Driven Guide to LASIK, PRK, and EVO ICL

The Question We Hear Every Day

You’ve been thinking about vision correction surgery. Maybe you’re tired of glasses or contacts. Maybe you’ve heard about LASIK from a friend. But here’s what we hear most often from patients considering their options: “How do I know this recommendation is right for me—and not just what your practice wants to sell me?”

That’s a fair question. And it deserves a straightforward answer.

At Diagnostic Eye Center in Houston, we believe the best vision correction decision starts with understanding the medical criteria that determine candidacy, not marketing hype. This guide walks you through how we—and any reputable eye surgeon—actually determine which procedure (LASIK, PRK, or EVO ICL™) is medically appropriate for your eyes. By the end, you’ll understand not just the procedures themselves, but the framework we use to recommend them.

Understanding the Three Main Vision Correction Options

Before we talk about candidacy, let’s clarify what each procedure actually does:

LASIK (Laser-Assisted In Situ Keratomileusis) uses a laser to reshape your cornea after creating a thin flap. It’s the most well-known procedure because it offers fast recovery and excellent visual outcomes for the right candidates.

PRK (Photorefractive Keratectomy) also uses a laser to reshape your cornea, but without creating a flap. Instead, the outer layer of the cornea (epithelium) is gently removed and naturally regenerates. It’s ideal for patients whose corneas are too thin for LASIK.

EVO ICL (Implantable Collamer Lens) takes a different approach entirely. Rather than reshaping your cornea, a tiny, prescription-correcting lens is surgically implanted inside your eye, in front of your natural lens. It’s reversible and doesn’t remove any corneal tissue.

The key insight: These aren’t competing options—they’re different tools for different eyes.

Who Is an Ideal Candidate? The Medical Framework

This is where the real decision-making happens. Here’s how we evaluate candidacy:

LASIK Candidacy: The Fast-Track Option

LASIK works best for patients who meet these criteria:

• Corneal thickness: At least 480 micrometers (measured via pachymetry). LASIK removes corneal tissue, so we need to ensure enough remains to maintain corneal integrity long-term.
• Stable prescription: Your vision prescription hasn’t changed significantly for at least 12 months. Unstable prescriptions mean we can’t predict the final outcome accurately.
• Mild to moderate refractive error: LASIK is FDA-approved for myopia up to -12.00 diopters, hyperopia up to +6.00 diopters, and astigmatism up to 6.00 diopters. Beyond these ranges, other procedures may be safer.
• Healthy corneas: No keratoconus, corneal scarring, or severe dry eye disease. These conditions compromise the cornea’s ability to heal properly after reshaping.
• Age 18+: Your eyes should be fully developed.
• Realistic expectations: You understand that LASIK corrects refractive error but doesn’t prevent presbyopia (age-related reading difficulty) or other age-related changes.

Why some patients aren’t LASIK candidates: If your corneas are thin, your prescription is very high, or you have corneal irregularities, LASIK may not be safe—not because we want to upsell you, but because the procedure carries higher risk of complications like undercorrection or corneal ectasia (progressive corneal weakening).

PRK Candidacy: The Surface-Smart Option

PRK is often recommended for patients who want LASIK but don’t meet the corneal thickness requirement. Ideal candidates include:

• Thinner corneas: PRK removes less corneal tissue overall because there’s no flap creation. If your pachymetry reading is 400-480 micrometers, PRK may be safer than LASIK.
• Active lifestyles or contact sports: Since there’s no corneal flap, there’s no risk of flap dislocation from trauma. Athletes and military personnel often choose PRK for this reason.
• Mild to moderate prescriptions: Like LASIK, PRK works best for myopia up to -12.00 diopters and similar ranges for hyperopia and astigmatism.
• Stable vision: Same 12-month stability requirement as LASIK.
• Healthy ocular surface: PRK requires a healthy epithelium to regenerate properly post-procedure.

The trade-off: PRK has a longer visual recovery (4-6 weeks for optimal vision vs. 24-48 hours for LASIK). Some patients experience mild discomfort during the epithelial healing phase. But the long-term outcomes are equivalent to LASIK—this is simply a different healing timeline.

EVO ICL Candidacy: The Lens-Based Option

EVO ICL opens doors for patients who don’t qualify for laser procedures. Ideal candidates include:

• High myopia: EVO ICL excels at correcting very high levels of nearsightedness (up to -20.00 diopters or beyond). If your prescription is -12.00 or higher, EVO ICL may offer superior outcomes.
• Thin corneas: Since no corneal tissue is removed, corneal thickness is irrelevant. Patients with pachymetry readings below 400 micrometers can safely have EVO ICL.
• Corneal irregularities: Keratoconus, post-LASIK ectasia, or other corneal shape abnormalities don’t disqualify you from EVO ICL, but your surgeon will discuss your visual potential if any of these conditions affect your eye’s ability to see well
• Age range: Typically 21-45 years old.
• Anterior chamber depth: Your eye must have sufficient space for the lens. This is measured during your comprehensive evaluation.
• Healthy retina and optic nerve: Since the lens is implanted inside the eye, we need to ensure your retina and optic nerve are healthy.

The reversibility advantage: Unlike LASIK and PRK, EVO ICL can be removed or exchanged if your prescription changes significantly or if you develop presbyopia and want a different correction strategy. This is a major advantage for younger patients or those with unstable prescriptions.

What About Dry Eye and Comfort?

This is a critical consideration that doesn’t always get enough attention in procedure comparisons.

LASIK and dry eye: Creating a corneal flap temporarily disrupts corneal nerves, which can reduce tear production for 3-6 months post-procedure. Most patients recover normal tear function, but some experience persistent dry eye. If you already have moderate to severe dry eye disease, LASIK may worsen symptoms.

PRK and dry eye: PRK also affects corneal nerves, but the healing process is more gradual. Some studies suggest PRK may result in slightly less post-operative dry eye than LASIK, though individual variation is significant.

EVO ICL and dry eye: Because no corneal tissue is removed and no flap is created, EVO ICL has minimal impact on tear production. If dry eye is a concern, EVO ICL is often the most comfortable choice.

Our approach: We perform comprehensive dry eye testing (corneal staining, tear break-up time, meibomian gland evaluation) before recommending any procedure. If you have significant dry eye, we may recommend pre-operative treatment or suggest EVO ICL as the safer option.

Recovery Timelines: What Real Life Looks Like

Understanding recovery isn’t just about when you can see clearly—it’s about when you can return to work, exercise, and normal activities.

LASIK Recovery

Day 1: Vision improves dramatically; most patients see 20/40 or better by morning after surgery. You can return to desk work and light exercise. Avoid eye makeup the first week.

Week 1: Vision continues improving; most patients achieve 20/20 or better. You can resume eye makeup, but avoid swimming and hot tubs until 2 weeks after LASIK.

Week 2-4: Vision stabilizes. Dryness gradually improves.

Month 3: Final vision stabilization; any residual dry eye typically resolves.

PRK Recovery

Days 1-3: Vision is blurry; the epithelium is regenerating. Mild discomfort is normal and managed with prescribed eye drops and pain medication. Most patients take the first few days off work.

Week 1: Vision begins improving as epithelium heals. You can resume light activities and exercise. You should avoid eye makeup for the first week.

Week 2-4: Vision improves significantly, though it may still be slightly blurry.

Week 4-6: Vision continues refining. Most patients achieve final vision by 6 weeks, though some take 3 months. Dryness also gradually improves.

Month 3: Final vision stabilization.

EVO ICL Recovery

Day 1: Vision improves quickly; most patients see 20/40 or better by the next morning.

Week 1: Vision continues improving; most achieve 20/20 or better. Recovery is similar to LASIK.

Week 2-4: Vision stabilizes. You can resume normal activities.

Month 1: Final vision achieved; minimal dry eye or discomfort.

The bottom line: LASIK and EVO ICL offer faster recovery, while PRK requires patience but delivers equivalent long-term results.

Long-Term Safety and Outcomes: What the Data Shows

All three procedures have strong safety profiles when performed on appropriate candidates. Here’s what clinical research demonstrates:

LASIK: Decades of clinical data support LASIK’s safety and efficacy. The vast majority of patients achieve their target vision correction. Serious complications are uncommon. Corneal ectasia (progressive corneal weakening) is a recognized but rare risk, and occurs almost exclusively in patients with pre-existing corneal weakness or those who shouldn’t have been candidates in the first place (thin corneas, keratoconus, etc.).

PRK: Long-term clinical outcomes are comparable to LASIK. Because PRK removes corneal tissue more gradually through epithelial regeneration rather than flap creation, some research suggests potentially lower rates of certain complications. Serious complications remain uncommon.

EVO ICL: Clinical studies and FDA approval data demonstrate excellent safety and efficacy. Serious complications are rare. The lens is designed to be a permanent implant, though it can be removed or exchanged if your vision needs change. Long-term follow-up studies support sustained safety and stability.

What this means: When performed on appropriate candidates, all three procedures have demonstrated safety and effectiveness. The “best” procedure isn’t the one with the best marketing—it’s the one that matches your eyes’ specific characteristics and medical profile.

The Candidacy Comparison Table

When Surgery Might Not Be Recommended (And That’s Okay)

Here’s something you won’t see in most marketing materials: sometimes, the most medically appropriate recommendation is not to have surgery.

We may recommend against vision correction surgery if:

Your prescription is unstable: If your vision is still changing year-to-year, we can’t predict the final outcome. We typically wait until your prescription has been stable for 12+ months.

You have uncontrolled dry eye disease: Surgery will worsen dry eye temporarily. If your dry eye is severe, we may recommend treating it first—or suggesting EVO ICL as a safer alternative.

You have corneal disease: Keratoconus, corneal scarring, or other corneal pathology may make surgery unsafe. In these cases, we focus on managing the underlying condition.

You have unrealistic expectations: If you expect surgery to eliminate presbyopia (age-related reading difficulty) or correct vision to better than 20/20, we’ll discuss realistic outcomes first.

You have active eye disease: Uncontrolled glaucoma, retinal disease, or other conditions affecting the back of the eye may require treatment before considering refractive surgery.

You’re pregnant or nursing: Hormonal changes can affect vision stability. We recommend waiting until 3 months postpartum and after nursing is complete.

Why we say no: Recommending surgery to someone who isn’t a good candidate doesn’t help them—it sets them up for disappointment or complications. Our job is to protect your vision first, and recommend surgery second.

The Three-Question Decision Framework

Before your consultation, ask yourself these three questions:

1. What’s my primary motivation?

Convenience (tired of glasses/contacts)? → LASIK or EVO ICL

Active lifestyle/sports? → PRK or EVO ICL

Very high prescription? → EVO ICL

Concerned about dry eye? → EVO ICL

2. What are my corneal characteristics?

Thick, healthy corneas? → LASIK is an option

Thinner corneas? → PRK or EVO ICL

Irregular corneas? → EVO ICL only

Unsure? → We’ll measure during your evaluation

3. What’s my timeline?

Need fast recovery? → LASIK or EVO ICL

Can wait 4-6 weeks? → PRK is an option

Want reversibility? → EVO ICL

Your answers to these questions will guide the conversation during your consultation—but they’re not the final decision. Your eye measurements, corneal topography, and overall eye health will determine what’s actually safe and appropriate for you.

How Diagnostic Eye Center Determines Your Recommendation

We don’t recommend procedures based on what we want to perform or what’s most profitable. Here’s our actual process:

Comprehensive eye exam: We measure your vision, eye pressure, corneal thickness, corneal shape, and overall eye health.

Advanced imaging: Corneal topography, anterior segment OCT, and other imaging help us understand your cornea’s exact characteristics.

Dry eye assessment: We test tear production and quality to understand your ocular surface health.

Lifestyle discussion: We talk about your daily activities, visual demands, and expectations.

Medical recommendation: Based on all this data, we recommend the procedure (or procedures) that are medically safe and appropriate for your eyes.

Your decision: You choose whether to proceed, and which procedure if multiple options exist.

Notice what’s missing: Pressure to choose the most expensive option, or to have surgery if you’re not a good candidate. Our goal is to help you make an informed decision based on your eyes’ specific needs—not our practice’s financial interests.

Realistic Expectations: What Surgery Can and Can’t Do

Vision correction surgery is transformative for the right candidates. But it’s not magic.

What surgery can do:

• Correct myopia, hyperopia, and astigmatism
• Reduce or eliminate your dependence on glasses and contacts
• Improve your quality of life and daily convenience
• Provide stable, long-term vision correction

What surgery can’t do:

• Prevent presbyopia (age-related reading difficulty, typically starting around age 40)
• Treat eye diseases like glaucoma, macular degeneration, or cataracts
• Guarantee 20/20 vision (though 95%+ of appropriate candidates achieve this)

The presbyopia conversation: If you’re over 40 or approaching 40, we’ll discuss monovision (correcting one eye for distance, one for near) or other strategies. This is a realistic conversation, not a sales pitch.

Frequently Asked Questions

Is LASIK permanent?

Yes. The corneal reshaping is permanent. However, your eyes can change over time due to aging, hormonal changes, or other factors. About 10% of patients need an enhancement procedure 5-10 years after their initial surgery.

Can I have LASIK if I have astigmatism?

Yes. LASIK corrects astigmatism up to 6.00 diopters. We’ll measure your astigmatism during your evaluation to confirm you’re a candidate.

What if I’m not a candidate for LASIK?

That’s where PRK or EVO ICL come in. We’ll discuss which alternative is best for your specific situation. Being “not a candidate for LASIK” doesn’t mean you can’t have vision correction surgery—it just means a different procedure may be safer for your eyes.

How much does each procedure cost?

LASIK and PRK typically cost $2,000-3,000 per eye. EVO ICL typically costs $4,000-6,000 per eye. We offer financing options and can discuss them in detail at your consultation.

Can EVO ICL be removed?

Yes. Unlike LASIK and PRK, EVO ICL can be removed or exchanged if your prescription changes significantly or if you develop presbyopia and want a different correction strategy. This reversibility is a major advantage for younger patients.

Will I need reading glasses after surgery?

If you’re over 40, yes—eventually. Vision correction surgery corrects distance vision but doesn’t prevent presbyopia. We can discuss monovision or other strategies to minimize your dependence on reading glasses.

Ready for Your Personalized Plan?

The best vision correction procedure for you isn’t determined by marketing or price—it’s determined by your eyes’ specific characteristics, your lifestyle, and your expectations.

At Diagnostic Eye Center in Houston, we’re committed to recommending what’s medically right for you, even if that means suggesting you wait, recommending a procedure you didn’t expect, or being honest about limitations.

Your next step: Schedule a comprehensive evaluation. We’ll measure your corneas, assess your eye health, discuss your lifestyle, and give you a clear, honest recommendation. No pressure. No sales pitch. Just the medical facts you need to make the best decision for your vision.

Schedule Your Vision Correction Consultation

Quick Reference: At-a-Glance Comparison

LASIK: Fast recovery, proven track record, best for healthy corneas with mild-moderate myopia

PRK: Ideal for thin corneas or athletes, longer recovery, equivalent long-term results to LASIK

EVO ICL: Best for high myopia or thin corneas, reversible, minimal dry eye impact, fastest recovery after LASIK

The right procedure is the one that matches your eyes—not the one with the best marketing.