It’s quite interesting how different industries establish specific vocabularies. It’s quite useful for people operating in that space as it help accelerate understanding between parties, however it can also be pretty daunting for external parties who aren’t familiar with those words.
Sounds familiar? Well, I’m not talking about computers this time, but about contact lenses. I’ve heard some of the terms before, as I wear lenses myself, but came across a page that explains what all the markings on your contact lens box are. Here’s what it says:
- Sph means sphere and determines the spherical power of the lens. If the value is negative it means that you are myopic or “short-sighted”, if the value is positive you are hyperopic or “long sighted”.
- BC means base curve and determines the radical curvature of the back surface of the lens.
- Dia means diameter and tells us how far it is straight across the lens from edge to edge.
- Cyl means cylinder. This number tells us how big astigmatism the lens corrects (optional)
- Axis determines in which direction the astigmatism lays (optional)
Do you wear lenses? I’ve been using disposable contact lenses for some time now and I’m quite happy with how they correct my eyesight and still allow me maximum flexibility.