Why Multi Purpose Contact Lens Solutions Have Preservatives?!
Question: Why Multi Purpose Contact Lens Solutions Have Preservatives?
Some contact lens rewetting eye drops emphasize preservative-free. What is the problems with preservative to the eyes?
Answers:
Best Answer - Chosen by Voters
[Frank..]
Every solution, designed to be opened/exposed to the air will get contamination from microbes in the air. Now if you want to keep that solution for a long time, it MUST have some kind of preservative to 'fight' the microbes that enter it from the air. This is no different to food, that has preservatives to stop it from spoiling quickly.
Solutions that don't have preservatives must be made sterile, and once opened, must be COMPLETELY used up, and NOT stored away. These are Single Use eye drops/rewetting drops, or aerosol type bottles.
As for eye problems with preservatives. Most people don't have any reactions to preservatives... but some people may have (usually minor) allergies to particular types of preservatives.
There are 'multipurpose' solutions that uses Hydrogen Peroxide to kill the microbes... and if used properly, the resulting solution after disinfecting your CL's, is plain water... (no preservatives)... but for these, you must follow the instructions STRICTLY, otherwise, you can accidentally put peroxide into your eye, which will BURN them.... not good!!!