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So the thing you need to know is there's 2 categories of soft contacts that are currently on the market. Hydrogels and Silicone Hydrogels (SiHy). The latter are newer and have become much more common as they are in theory healthier for the eye (they allow more oxygen to pass through). There's some drawbacks though in that the material isn't inherently wettable because silicone is hydrophobic by nature. This means it's a bit more complex to formulate a material and there's some quirks to it, notably it's usually stiffer. This might affect how solutions interact with the surface.

Corneal staining is basically scratching of the outer part of your eye. It is usually asymptomatic but can result in a burning sensation. It was found that the surface of SiHy is affected by what material is used to clean them. This link includes some research and plenty of linked studies: https://contactlensupdate.com/2013/08/14/what-do-we-know-abo... I had a better link that compared various products on the market but I'm unable to find it as this time.




Interesting. That link seems to say they aren't even really confident what staining is, it could just be the fluorescin dye binding to the eye. My friend wears Night & Day (SiHy) and rarely takes them out at night, replaces them maybe every 1-2 months. Mostly no issues or burning, although he did get a corneal ulcer one time, and he has seen increased neovascularization.


Correct, by no means am I claiming it's dangerous to use standard MPS, but I understand the mechanism of action with hydrogen peroxide better and it seems extremely effective. I wear Cooper Biofinity's and rarely take them out, aside from a minor abrasion that caused me not to be able to wear contacts for a month a couple years ago, they've been drama-free.

However, peroxide solution does have some big drawbacks. The better two-stage systems where you add a neutralizing solution to the peroxide when you're about to put the lenses back in I haven't been able to find in the US, and this is the safest gold standard (as you're leaving max disinfection power until right before you get them in your eyes). All that's sold are 1-step systems with a catalyst disk/ring at the bottom of a special case.

While I haven't had issues with the catalyst wearing off of the Clear Care cases, some of the other brands seem to not work as well and if the lens case is left in a sub-60F room, it will not neutralize in time. Honestly, this wasn't something on their documentation and if I wanted to be a pain about it I could probably put a consumer safety claim in. Putting un-neutralized peroxide solution in your eyes is a pretty traumatizing experience, worse than hot sauce. I don't recommend it!

EDIT: I'm not an optometrist/opthamologist, but I'll tell you how I got the background on this stuff: I did a project with some dude on IRC that was like the human bat, he had severe photophobia. We studied quite a bit about the characteristics of various contact lens technologies in preparation for our project. He wanted to acquire tinted contacts and vary the % of opacity. (I'm aware J&J is selling transitions contacts now and unsure of their efficacy but at the time the only options were extremely expensive traditional hydrogels.)

Long story short: We downloaded a bunch of patents and he built a small lab and dyed his own hydrogels using their patented processes. It was a neat and very illegal project, but he got his own sun contacts so he didn't have to live in his cave anymore and I got a ton of semi-useless knowledge.




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