I’ve recently gotten my first pair of contact lenses, and after reading the pamphlet that comes with the cleaning solution, I’m a little worried. They mention severe things such as eye ulcers (new one on me) and loss of vision as possibilities, though they credit it to smoking while wearing contacts.
After looking at the ingredients to this cleaning solution (buffered, isotonic, aqueous solution containing sodium citrate, sodium chloride, boric acid, sorbitol, AMP-95, Tetronic 1304, with edetate disodium 0.05%, Polyquaternium-1 0.0001% and myristamidopropyl dimethylamine 0.0005%), I’m wondering if half of the problems they’ve had in control groups aren’t from the very ingredients of their cleaning solution.
Boric acid? I’m no chemist, I can’t even begin to pronounce some of those chemical compounds, but from what little I do know, acid in your eye isn’t a good thing.
I’ve also had a problem with keeping the lenses moist, so I purchased some Clear Eyes CLR, and it contains sorbic acid.
My question is, just what is boric and sorbic acid, and is it something one should be putting into such a sensitive organ as the eye? (fully understanding a search on google would reveal gobs of info, but looking for a layman’s explanation of things, as I don’t speak chemistese)
Of course, if it were really dangerous, then it wouldn’t be in there. I have bad allergies and I’ve used boric acid eyewashes many times. I would imagine that the final pH of any eye solution is carefully controlled. I cannot wear contacts because my eyes are too sensitive to foreign objects. If you find that the solution you are using irritates your eyes, I would suggest rinsing your contacts with the hypoallergenic saline solutions they sell in drugstores before putting them in your eyes.
A dilute solution of boric acid acts as an antiseptic. As a kid I had conjuctivitis on two separate occasions and my mother mixed up a boric acid solution as an eyewash. It worked just fine and cleared up the infection in no time.
Many things are referred to as acids, even when in the basic form. Carboxylic acids, for example, are frequently deprotonated in the form in which you encounter them.
Your eye may very well not be pH7. Then again, it could be. I dunno.
I’ve had no experience with boric acid, but the MSDS indicates that it’s not a carcinogen, has been “investigated as a mutagen”, and doesn’t list anything worse than “irritation” for eye contact effects. Given that your solution is probably of minimal concentration (and that it is a mass-marketed product which probably hasn’t blinded anybody yet), I wouldn’t worry too much about it.
The key words to understanding the ingredient list are “buffered” and “isotonic.” Buffered implies that the pH of the stuff is adjusted to somewhere near the normal pH of your eyeball. Isotonic means that the solution contains the same amount of salt as do regular tears.
So, regardless of what strange chemicals are in it, the solution has been adjusted to an acidity that won’t hurt the eyes, and a salt level that doesn’t sting.
And if it’s the word “acid” that’s worrying you, just remember that vinegar is a solution of acetic acid, and you probably have consumed some of that in your life! Though of course, I wouldn’t put it in my eye…so maybe this isn’t all that relevent a point…
