{"id":6556,"date":"2026-08-20T11:07:31","date_gmt":"2026-08-20T11:07:31","guid":{"rendered":"https:\/\/www.1800getlens.com\/eyetopics\/?p=6556"},"modified":"2026-08-20T12:37:26","modified_gmt":"2026-08-20T12:37:26","slug":"lasik-vs-prk-vs-smile-vs-evo","status":"publish","type":"post","link":"https:\/\/www.1800getlens.com\/eyetopics\/lasik-vs-prk-vs-smile-vs-evo\/","title":{"rendered":"LASIK vs PRK vs SMILE vs EVO: Animations of How Each Work"},"content":{"rendered":"\n<div class=\"gl-anim-post\"><style>\n.gl-anim-post{max-width:880px;margin:0 auto;}\n.gl-anim-post p{line-height:1.7;}\n.gl-anim-post p.standfirst{font-size:1.15em;line-height:1.6;}\n.gl-anim-post h2{margin-top:2em;}\n.gl-anim-post figure{margin:2.2em auto;}\n.gl-anim-post figure.wp-block-video{width:min(1120px,calc(100vw - 40px));max-width:none;margin-left:50%;transform:translateX(-50%);}\n.gl-anim-post video{display:block;width:100%;height:auto;border-radius:6px;background:#050D15;}\n.gl-anim-post figcaption{font-size:.9em;color:#5a6472;margin-top:.7em;text-align:center;}\n.gl-anim-post figure.wp-block-table{overflow-x:auto;-webkit-overflow-scrolling:touch;}\n.gl-anim-post table{width:100%;border-collapse:collapse;font-size:.94em;min-width:560px;}\n.gl-anim-post th,.gl-anim-post td{border:1px solid #dde4ef;padding:10px 12px;text-align:left;vertical-align:top;}\n.gl-anim-post thead th{background:#f2f6fd;font-weight:600;}\n.gl-anim-post ul{line-height:1.7;}\n\n.gl-anim-post .gl-note{border-top:1px solid #dfe6ef;border-bottom:1px solid #dfe6ef;padding:24px 0;margin:2.2em 0;}\n.gl-anim-post .gl-note .gl-note-k{font-family:\"Futura PT\",Futura,\"Century Gothic\",sans-serif;font-weight:600;font-size:13px;line-height:1;letter-spacing:.18em;text-transform:uppercase;color:#0077DD;margin:0 0 12px;}\n.gl-anim-post .gl-note p:not(.gl-note-k){font-size:1.05em;line-height:1.55;margin:0;}\n\n.gl-anim-post h3.gl-full{font-size:27px;font-weight:500;line-height:1.25;margin:.15em 0 .9em;}\n.gl-anim-post h3{margin-top:1.5em;}\n.gl-anim-post h4{font-size:22px;font-weight:700;color:#2b3440;margin:2em 0 .45em;line-height:1.3;}\n\n.gl-anim-post ul{line-height:1.65;padding-left:1.3em;margin:.9em 0 0;}\n.gl-anim-post li{margin-bottom:.6em;}\n.gl-anim-post p.gl-caveat{font-size:.88em;color:#5a6472;margin-top:1em;}\n<\/style><!--BODY--><p class=\"standfirst\"><strong>All four of these procedures fix the same problem, of light landing in the wrong place inside your eye. What differentiates them is which tissue the surgeon touches to get there. Each one is animated, with step by step commentary.<\/strong><\/p>\n\n<p>If you&#8217;ve looked into vision correction, you&#8217;ve almost certainly been handed a list of acronyms with a price next to each one. That&#8217;s not much help, because the price isn&#8217;t the real difference. The real difference is anatomical. Two of these procedures reshape your cornea with a laser, one carves a piece out of it and removes it whole, and one leaves the cornea alone entirely and puts a lens inside your eye.<\/p>\n\n<p>Once you can see that, the trade-offs stop being marketing claims and start being straightforward. So rather than describe them, we animated them. Every measurement on screen is a real one, at real proportions: a cornea is about 540 microns thick, roughly half a millimeter, and the animations hold to that.<\/p>\n\n<h2>Start with the cornea<\/h2>\n\n<p>Your cornea, the clear dome at the front of your eye, does about two-thirds of your eye&#8217;s focusing. It&#8217;s roughly half a millimeter thick and made of layers. If it focuses light slightly too strongly, that light lands short of your retina and distance vision blurs. That&#8217;s nearsightedness, and flattening the center of the cornea by a few dozen microns corrects it.<\/p>\n\n<p>Every procedure below is a different answer to one question: how do you get to that tissue, or avoid needing to?<\/p>\n\n<h2>LASIK<\/h2>\n\n<h3 class=\"gl-full\">Laser-assisted in situ keratomileusis<\/h3>\n\n<figure class=\"wp-block-video\">\n<video controls=\"controls\" preload=\"metadata\" playsinline=\"playsinline\" width=\"1280\" height=\"720\" style=\"width:100%;height:auto;display:block\" poster=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/lasik-animation-poster.jpg\" src=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/lasik-animation.mp4\" aria-label=\"Animation of the LASIK procedure in corneal cross-section\"><\/video>\n<figcaption>LASIK, step by step. Cross-section drawn at true proportions.<\/figcaption>\n<\/figure>\n\n<p>LASIK is the one most people have heard of. It works in two stages, with two different lasers. First a femtosecond laser lays a plane of microscopic bubbles about 110 microns below the surface, outlining a thin flap roughly 9 mm across, and deliberately leaves one edge uncut as a hinge. The surgeon folds that flap back like the cover of a book.<\/p>\n\n<h4>What the second laser does<\/h4>\n\n<p>That exposes the stroma, the thick structural middle layer. A second laser, an excimer, then removes tissue from it. Excimer light is cool ultraviolet: it breaks molecular bonds rather than burning, so nothing heats up. The flap is floated back down afterward and seals by natural suction. No stitches.<\/p>\n\n<div class=\"gl-note\">\n<p class=\"gl-note-k\">In real terms<\/p>\n<p>For a moderate prescription of about \u22124.00, the laser removes roughly 52 microns from the center of your cornea. That&#8217;s around a tenth the thickness of a sheet of paper.<\/p>\n<\/div>\n\n<h4>Why does LASIK recover so fast?<\/h4>\n\n<p>Because the surface layer rides back into place on the flap, the eye&#8217;s outer skin is never left open. That&#8217;s why most people see well the next morning. The trade-off is that the flap becomes a permanent structural feature of the cornea, and a thin cornea may not have enough tissue to safely make one.<\/p>\n\n<h4>LASIK may be right for you if:<\/h4>\n\n<ul>\n<li>You&#8217;re at least 18, and your prescription hasn&#8217;t moved more than about 0.50 D in the past year.<\/li>\n<li>Your cornea is thick enough to carry a flap, generally above 500 microns, leaving at least 250 microns underneath once the laser has finished.<\/li>\n<li>Your prescription sits in the treatable range: up to roughly \u22129.00 D of nearsightedness, about +4.00 D of farsightedness, and up to 5.00 D of astigmatism.<\/li>\n<li>A fast turnaround suits your life, since most people see well the next morning.<\/li>\n<li>You don&#8217;t have keratoconus, uncontrolled glaucoma, an active eye infection, or an autoimmune condition that slows healing.<\/li>\n<li>You&#8217;re not pregnant or nursing, because the hormones shift your prescription.<\/li>\n<\/ul>\n\n<p class=\"gl-caveat\">Corneal mapping can still rule you out when every line above fits. That&#8217;s what the scans are for.<\/p>\n\n<h2>PRK<\/h2>\n\n<h3 class=\"gl-full\">Photorefractive keratectomy<\/h3>\n\n<figure class=\"wp-block-video\">\n<video controls=\"controls\" preload=\"metadata\" playsinline=\"playsinline\" width=\"1280\" height=\"720\" style=\"width:100%;height:auto;display:block\" poster=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/prk-animation-poster.jpg\" src=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/prk-animation.mp4\" aria-label=\"Animation of the PRK procedure in corneal cross-section\"><\/video>\n<figcaption>PRK. Note the identical laser step, and what happens instead of a flap.<\/figcaption>\n<\/figure>\n\n<p>PRK is the original laser vision correction procedure, and it&#8217;s still the right answer for a lot of people. Watch the animation against the LASIK one and you&#8217;ll see the reshaping step is <em>the same<\/em>: the same excimer laser, the same depth, the same optical zone.<\/p>\n\n<h4>How the surgeon reaches the tissue<\/h4>\n\n<p>Instead of cutting a flap, the epithelium, the eye&#8217;s thin surface skin at about 50 microns, is loosened with dilute alcohol and lifted away entirely. The laser then works on the bare surface. A soft bandage <a href=\"https:\/\/www.1800getlens.com\/contacts\/\" title=\"contact lens\">contact lens<\/a> goes on afterward and stays three to five days while that surface grows back from the edges inward.<\/p>\n\n<h4>What PRK trades away, and what it buys<\/h4>\n\n<p>PRK trades comfort for structure. There&#8217;s no flap, ever, so there&#8217;s nothing to dislodge and no depth taken up by one. That makes it a strong option for thinner corneas, or for people whose work or sport carries a real risk of a knock to the eye.<\/p>\n\n<p>The cost is the first few days. Vision is genuinely hazy while the surface closes, and full sharpness keeps improving for weeks rather than overnight.<\/p>\n\n<h4>PRK may be right for you if:<\/h4>\n\n<ul>\n<li>Your cornea is too thin for a flap, or an earlier procedure has already used up the depth. PRK needs less tissue because it never cuts one.<\/li>\n<li>You box, wrestle, do martial arts, or work somewhere a blow to the eye is a live possibility. The FDA names contact sports specifically as a reason to avoid a flap.<\/li>\n<li>You get recurrent corneal erosions, or you have epithelial basement membrane dystrophy, where lifting a flap carries real risk.<\/li>\n<li>You already run dry, which surface treatment tends to handle better over the long run.<\/li>\n<li>You can live with a slower start: several days of hazy vision while the surface closes, then weeks of gradual sharpening.<\/li>\n<li>Your prescription has held within 0.50 D for a year and falls inside roughly \u221212 D of nearsightedness, 6 D of astigmatism, or 5 D of farsightedness.<\/li>\n<\/ul>\n\n<p class=\"gl-caveat\">Lower prescriptions do better here. The higher the correction, the more likely some of it drifts back.<\/p>\n\n<h2>SMILE<\/h2>\n\n<h3 class=\"gl-full\">Small incision lenticule extraction<\/h3>\n\n<figure class=\"wp-block-video\">\n<video controls=\"controls\" preload=\"metadata\" playsinline=\"playsinline\" width=\"1280\" height=\"720\" style=\"width:100%;height:auto;display:block\" poster=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/smile-animation-poster.jpg\" src=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/smile-animation.mp4\" aria-label=\"Animation of the SMILE procedure in corneal cross-section\"><\/video>\n<figcaption>SMILE. The tissue isn&#8217;t vaporized. It leaves as one solid piece.<\/figcaption>\n<\/figure>\n\n<p>SMILE is the newest of the three laser procedures and it works on a different principle. There&#8217;s no excimer laser at all, and no flap. A single femtosecond laser makes two cuts <em>inside<\/em> the cornea: one along the bottom of a disc-shaped piece of tissue, one along the top. Between them sits a thin lens-shaped disc, the lenticule.<\/p>\n\n<h4>How the lenticule comes out<\/h4>\n\n<p>The laser also cuts a small opening at the edge, two to four millimeters wide. The surgeon goes in through that opening, separates the lenticule and draws it out whole. Nothing is vaporized. A piece of tissue is removed as an object, and the cornea settles slightly flatter because that volume is now gone.<\/p>\n\n<h4>What stays intact with SMILE?<\/h4>\n\n<p>The front surface is never opened, so the corneal layer over the treatment stays continuous. The small incision also means fewer of the corneal nerves are cut, which is why SMILE tends to come up in conversations about less post-op dryness.<\/p>\n\n<p>The main practical limit is range. SMILE is used primarily for nearsightedness with or without astigmatism, and it isn&#8217;t the tool for farsightedness.<\/p>\n\n<h4>SMILE may be right for you if:<\/h4>\n\n<ul>\n<li>You&#8217;re 22 or older, with a prescription that hasn&#8217;t moved more than 0.50 D in the past year.<\/li>\n<li>You&#8217;re nearsighted up to about \u221210.00 D, with astigmatism up to \u22123.00 D.<\/li>\n<li>Your central cornea measures above roughly 475 microns.<\/li>\n<li>Dry eye worries you. The small incision cuts fewer corneal nerves than a full flap does.<\/li>\n<li>You have large pupils, or you play contact sports, where having no flap works in your favor.<\/li>\n<li>You&#8217;re nearsighted rather than farsighted. SMILE isn&#8217;t approved for hyperopia in the US.<\/li>\n<\/ul>\n\n<p class=\"gl-caveat\">If your cornea has an irregular surface or significant scarring, a surface treatment usually suits you better.<\/p>\n\n<h2>EVO ICL<\/h2>\n\n<h3 class=\"gl-full\">Implantable collamer lens<\/h3>\n\n<figure class=\"wp-block-video\">\n<video controls=\"controls\" preload=\"metadata\" playsinline=\"playsinline\" width=\"1280\" height=\"720\" style=\"width:100%;height:auto;display:block\" poster=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/evo-icl-animation-poster.jpg\" src=\"https:\/\/www.1800getlens.com\/eyetopics\/wp-content\/uploads\/2026\/08\/evo-icl-animation.mp4\" aria-label=\"Animation of the EVO ICL procedure inside the eye\"><\/video>\n<figcaption>EVO ICL. The cornea is never reshaped. A lens is added behind the iris.<\/figcaption>\n<\/figure>\n\n<p>The EVO ICL is the odd one out, and deliberately so. No tissue is removed and the cornea is never reshaped. Instead a soft, flexible lens is placed permanently inside the eye, in the space between the iris and your own natural lens.<\/p>\n\n<h4>How the lens sits inside the eye<\/h4>\n\n<p>It goes in folded, through a 3 mm opening at the edge of the cornea, and unrolls once inside. Its four small feet tuck into a groove behind the iris that holds it in position. It doesn&#8217;t touch your natural lens: it arches over it, leaving a deliberate space called the vault. The EVO generation has a small central port, about a third of a millimeter wide, so the fluid inside your eye flows straight through it as normal.<\/p>\n\n<div class=\"gl-note\">\n<p class=\"gl-note-k\">In real terms<\/p>\n<p>Every other option here is permanent. The ICL can be taken back out if your eyes or your needs change, because nothing was removed to put it in.<\/p>\n<\/div>\n\n<h4>Who is the ICL for?<\/h4>\n\n<p>This is the procedure that exists for people the laser options don&#8217;t suit, whether that&#8217;s a very high prescription or a cornea too thin to safely reshape. The flip side of adding a lens rather than removing tissue is that this is intraocular surgery. The surgeon enters the eye itself, so the conversation about risk is a different one from a laser treatment on the surface.<\/p>\n\n<h4>EVO ICL may be right for you if:<\/h4>\n\n<ul>\n<li>You&#8217;re between 21 and 60. The FDA widened that range from 21 to 45 in February 2026.<\/li>\n<li>You&#8217;re nearsighted between \u22123.0 D and \u221220.0 D, with up to 4.0 D of astigmatism using the toric version.<\/li>\n<li>Your cornea is too thin to reshape safely, or your prescription runs too high for a laser to reach.<\/li>\n<li>Your anterior chamber measures at least 3.00 mm deep, and your endothelial cell count meets the minimum for your age.<\/li>\n<li>Being able to change your mind appeals to you, since the lens can come back out.<\/li>\n<li>You&#8217;re comfortable with surgery inside the eye, which carries a different risk profile from laser work on the surface.<\/li>\n<li>You&#8217;re not pregnant or nursing, and your angles aren&#8217;t narrow.<\/li>\n<\/ul>\n\n<p class=\"gl-caveat\">Anterior chamber depth and cell count are measured, not estimated. They decide this one before anything else does.<\/p>\n\n<h2>Side by side<\/h2>\n\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr><th><\/th><th>LASIK<\/th><th>PRK<\/th><th>SMILE<\/th><th>EVO ICL<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>What&#8217;s touched<\/strong><\/td><td>Corneal stroma, under a flap<\/td><td>Corneal stroma, from the surface<\/td><td>Corneal stroma, from inside<\/td><td>Nothing removed; lens added<\/td><\/tr>\n<tr><td><strong>Lasers used<\/strong><\/td><td>Two: femtosecond + excimer<\/td><td>One: excimer<\/td><td>One: femtosecond<\/td><td>None<\/td><\/tr>\n<tr><td><strong>Flap<\/strong><\/td><td>Yes, hinged, ~110 \u00b5m deep<\/td><td>No<\/td><td>No, 2\u20134 mm incision<\/td><td>No, 3 mm incision<\/td><\/tr>\n<tr><td><strong>Typical visual recovery<\/strong><\/td><td>Next day<\/td><td>Several days, then weeks to sharpen<\/td><td>A day or two<\/td><td>Within a day or two<\/td><\/tr>\n<tr><td><strong>Typically considered when<\/strong><\/td><td>Cornea is thick enough and fast recovery counts<\/td><td>Cornea is thinner, or contact sport \/ job risk<\/td><td>Myopia \u00b1 astigmatism, dryness is a concern<\/td><td>Prescription is very high, or cornea too thin<\/td><\/tr>\n<tr><td><strong>Reversible<\/strong><\/td><td>No<\/td><td>No<\/td><td>No<\/td><td>Yes, the lens can be removed<\/td><\/tr>\n<\/tbody>\n<\/table>\n<figcaption>Figures are typical, not promises. Your own numbers come from your measurements.<\/figcaption>\n<\/figure>\n\n<h2>So which one is right for you?<\/h2>\n\n<p>Honestly, that&#8217;s not a question a blog post can answer, and you should be wary of any page that claims otherwise. The choice is driven by measurements of your own eyes: how thick your cornea is, its shape, your prescription, your pupil size, how dry your eyes run, plus how you live day to day. A boxer and an accountant with identical prescriptions may belong in different chairs.<\/p>\n\n<p>What these animations are for is the conversation. If you walk into a consultation already knowing that a flap is a real structural thing, that PRK&#8217;s slower start buys you the absence of one, that SMILE takes tissue out whole, and that the ICL adds rather than subtracts, you can ask much better questions. You&#8217;ll also be able to tell whether the answers you get are about your eyes or about a package.<\/p>\n\n<h2>Talk it through with someone who measures first<\/h2>\n\n<p>A consultation should start with your eyes, not with a procedure name. If you&#8217;d like to know which of these four you&#8217;re a candidate for, get in touch: <a href=\"https:\/\/www.1800getlens.com\/\">1-800-GET-LENS<\/a>.<\/p>\n\n<p><em>This article is general information about how these procedures work, not medical advice, and it can&#8217;t tell you which one suits you. Every figure quoted is a typical value, used to keep the animations accurate in proportion; your own measurements and treatment plan will differ. Suitability, risks and outcomes can only be determined by a qualified eye surgeon after a full examination. All four procedures carry risks, which your surgeon should explain to you in detail before you consent to anything.<\/em><\/p><!--\/BODY--><\/div>\n","protected":false},"excerpt":{"rendered":"<p>See all four vision correction procedures animated to true proportions. What each does to your eye, how they differ, and what to ask at your consultation.<\/p>\n","protected":false},"author":4,"featured_media":6562,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"semantictags":[],"class_list":["post-6556","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledge-center"],"_links":{"self":[{"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/posts\/6556","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/comments?post=6556"}],"version-history":[{"count":13,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/posts\/6556\/revisions"}],"predecessor-version":[{"id":6586,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/posts\/6556\/revisions\/6586"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/media\/6562"}],"wp:attachment":[{"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/media?parent=6556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/categories?post=6556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/tags?post=6556"},{"taxonomy":"semantictags","embeddable":true,"href":"https:\/\/www.1800getlens.com\/eyetopics\/wp-json\/wp\/v2\/semantictags?post=6556"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}