Here we stand at the trailhead of a journey through the different intra-ocular lens (IOL) choices. This will be a genuine nature walk – sightseeing these IOLs in their natural, uncommercialized setting. Usually, the only way to research IOLs is through highly manicured, carefully branded internet and brochure marketing. It’s research in a walled garden of buzzwords like “premium” and “freedom.”
Our goal here will be to climb over that wall and take a behind-the-scenes tour of the different IOLs.
The Monofocal Lens In Action
Today we begin the series with the monofocal IOL. Why start here? Well, two reasons: one, nothing about newer and flashier IOLs makes sense until you understand monofocal IOLs, and two, monofocals are the anchor in any lineup of IOLs.
Monofocal IOLs work by focusing light coming from a specific distance. One distance. Hence the “mono” in the name. Ever sat in a presentation where the speaker begins by fiddling around with the projector to get his slides in focus? That’s a monofocal lens in action. It will focus perfectly at that distance, but if you change the distance of the screen or projector it’s blurry.
Luckily, because of math that is so tedious I’ll skip it so we can stay friends, it works out that a monofocal IOL focused at distance covers a lot of range. Everything from the moon to about 20 feet away is equally sharp, and it’s really not until you get to about 5 feet away that blur becomes noticeable.
While the single (mono) focus may seem like a liability – no one likes reading glasses – it’s a virtue as well. The quality of the optics (which translates into how sharp the vision can be) is almost magical. With zero aberrations and maxed-out contrast sensitivity, monofocal lenses are unparalleled in simple, clean clarity of focus. There’s a reason the Hubble telescope is monofocal rather than multifocal.
Speaking of the Hubble, remember when it first got put in orbit and started taking blurry photos? NASA flew up there and fixed it and every photo became crystal clear. The problem they fixed was called spherical aberration. The difference between 2.2 millionths of a meter and zero spherical aberration is the difference between the photo on the left and right.
“Thanks, Neil deGrasse Tyson, can we talk about IOLs again?” you might say. But we are! Spherical aberration and a host of other higher-order aberrations (with even weirder names) are the real science behind monofocal IOLs that usually just gets simplified into words like “space-age” or “contrast sensitivity.”
It’s why I get so annoyed when I hear salesmen describing monofocals as the “standard, government issue IOL.” Its walled garden phrasing designed to create a negative reaction to an IOL that is a technological marvel. If your doctor recommends a monofocal as the best option (assuming they have access to all the options) then it’s by far the best option. The difference between happy miracle vision and annoying smudge vision. The galaxy on the right vs. the one on the left.
Consistent & Reliable Lens
This is why monofocal IOLs truly are the anchor of the IOL lineup. When I say “the anchor,” I mean it in every sense of the word – stability, security, and maybe most importantly, reliability. The monofocal IOL is like the TV show Seinfeld in NBC’s Thursday night lineup during the nineties. Remember that? New sitcoms popped up, then flourished or floundered, but Seinfeld just stayed popular and kept improving. Have I gotten distracted talking about Seinfeld? Maybe a little, but the point remains. Monofocal IOLs are still the most popular, most consistent IOL choice on Earth despite all the other options, because they’re tried and true, and just keep getting better. Just like mid-nineties Seinfeld.
The Best Possible Vision Already Here
Whether it’s IOLs, cars, clothes… you name it, a lot of money is spent on advertising to conflate “new” and “better” into the same word. With TV, it’s immediately obvious that new isn’t necessarily better (remember 2000’s Daddio? Me neither). With IOLs, sometimes that’s harder to recognize. New technology widens the borders of who can be helped and what kinds of glasses-free vision are possible. But some folks don’t need wider borders, the IOL they need for the best possible vision is already here. In those cases, “new” is just another second best and we’re grateful to have a perfect option anchoring the team.