Specifically, red plastic tips on bottles of contact lens solution that contains peroxide. Broadly speaking, there are two types of contact lens solution that disinfect your lenses: multi-purpose solution disinfects and dissolves protein and fat deposits on your lenses, and does not scorch your corneas. You do, however, have to rub the lenses to clean them.
Hydrogen peroxide disinfecting solution performs the same functions but doesn’t contain preservatives, and users do not need to rub the lenses to clean them, but if used to store lenses in a case not designed for use with peroxide solution, they can cause terrible pain and even serious injuries. .
Before 2012, manufacturers didn’t do much to differentiate the bottles, and this caused serious and painful problems. Back in 2010, we suggested putting a giant label on the bottles that says “DON’T PUT THIS IN YOUR EYES, DUMBASS,” but the eye care industry is smarter and added red warning labels and a red tip on all bottles that contain hydrogen peroxide solutions.
See? Progress. Thanks to some basic safety measures, contact lens wearers are significantly less likely to mix up bottles and cause injuries.