There are ages of particular importance in deciding which procedure would best fix your eyes. They seem arbitrary, and honestly, they are a little bit, but on a wider frame of reference, they are based on data from hundreds of thousands of eyes over the years.
Age 17? LASIK is a no go. When you turn 18, however, the option for LASIK opens up. Arbitrary cut off point, massively researched reason for it. The same type of age-based phenomenon is also true of RLE vs. LASIK.
After around age 48, it becomes obvious the lens inside your eye is not going to allow you easy distance and near vision. There are whispers—and sometimes shouts—leading up to this point, but 48 is when just about everyone starts ending up on the same page. LASIK can help at this age, and in almost every case it can help much better than RLE can. At 58, it is nearly always the opposite. RLE is the best option the vast majority of the time. Ten years and the tables turn, but why?
The idea behind RLE is that it can replace a lens that’s become dysfunctional enough in autofocus to require glasses. The lens, however, doesn’t become maximally dysfunctional overnight. It happens over several decades, starting when you’re a teenager. The difference is, back then, the lens was still so good it would be impossible to tell any loss of flexible autofocus. And that remains true for a few decades. We don’t start to notice till our forties.
It isn't until around age 70, however, that the lens becomes completely stiff and stuck — devoid of any autofocusing capability at all. I can say with certainty there is no 70-year-old with a natural lens that is better than a new intra-ocular lens. There may be reasons not to have surgery, but there is zero chance for one of those reasons to be the 70-year-old lens works better than a new lens would.
So as a 20-year-old, it’s a terrible idea to replace the lens because it is amazing. LASIK wins every time. As a 70-year-old, the natural lens would be superseded by a new lens in every case because the natural lens has lost all autofocus, not to mention it’s also turned a little yellow. RLE wins every time. Now with our anchor points, we can narrow in on when RLE starts to be a better idea than LASIK.
Depending on the prescription, it starts to be a competition between LASIK and RLE at age 50, and RLE starts to dominate as the better choice at age 55. The details of what determines the best procedure during those years are more specific and variable than would be worth writing here. I’m pretty impressed you’ve read this far as it is. It feels cruel to punish that kind of pursuit of knowledge with a long list anatomical and physiological details to be considered in this age range.
The final choice on candidacy hinges on what will give the best vision for the most time. When you’re 20, having a perfect prescription from LASIK and a natural perfectly-autofocusing lens for the next couple decades is hard to beat. In your 50s, the diagnostics can help us figure out how to accomplish the same goal: the best vision for the most time. LASIK may be best if your natural lens still has enough life and clarity left to give you more than a new lens could. If it happens to be RLE, then your natural lens has finished its lifetime of service and given you the gift of being a candidate for a procedure intended to be the last vision correction you’ll ever need.