Joel Hunter, MD Refractive Surgeon, Hunter Vision Updated 04/10/19 9:43 AM
You may have found in your ICL research that the letters don’t actually stand for Implantable Contact Lens, but instead for Implantable Collamer Lens. The only downside to knowing this is you still can’t use the correct term when talking to people about it. The common idea of it being an implantable contact is so common that you’ll be corrected (incorrectly) if you say “collamer” instead. It’s the same problem you’ll face with the phrase “champing at the bit.” (I know! I wish I’d never found out either.)
Is it like a contact?
The reason it’s worth making the distinction here is that an ICL doesn’t really look like a contact lens. The optical zone that stretches across a contact lens is somewhere around 13 millimeters—give or take—depending on the brand. That’s basically a little bigger than the diameter of the cornea, which you see in the mirror as colored part of your eye. An ICL doesn’t have to be anywhere near that large, because it doesn’t have to sit on the front of your eye. A medical device gets tailored to fit where it needs to sit. So contacts are sized to fit on the cornea.
An ICL doesn’t need to be sized for the cornea though, it needs to be sized to sit about 3 millimeters—again, give or take—behind the cornea where your pupil is. For that reason, the optic of an ICL is about 5 millimeters and it sits directly behind your pupil. There a transparent wings to the ICL to hold it in this place so tip to tip it is around 12.5 millimeters. Because of the wings, no sutures or other fasteners are needed. It rests naturally. It’s behind the pupil, and those wings aren’t seen because they’re behind-the-scenes support for the optic that corrects the vision.
This means that if you look at an ICL on a piece of paper next to a contact lens, the ICL looks tiny. 5 mm vs. 13 mm may seem like a small difference, but the surface area of the second one is about 650% greater. It’s a gigantic difference in size. That means two things:
1. The natural idea of “yikes, it’s hard to imagine a contact lens being in my eye,” is a thought experiment that never needs to occur. The lens designed to do this is much, much smaller and made to fit in a much more customized way.
2. I owe an apology to my sixth grade math teacher for telling him that I would never use the value of pi for my job some day. Mistakes were made in assuming that. For one, I thought I was going to be a chef at that time. But also, I clearly lacked the maturity to realize someone much smarter than me would have better perspective on this issue.
All in all, seeing photos will probably help supplement the idea of the structure of an ICL more than more words will. From here on it would be like trying to describe how to draw a horse instead of just seeing the drawing. A picture paints a thousand words when you’re trying to describe something. And if one of the words you’re avoiding is collamer or champing, even better.