http://www.greatcontactlens.net/contact-lenses-purevision/
Can one use Purevision (balafilcon A) contact lenses for regular use only - i.e. not extended wear?
I have been wearing Proclear Toric (omafilcon A) for some time and been very satisfied with them. Been thinking of trying the extended wear Purevision - main reason is that I want/need the option of occasionally wearing them overnight (backpacking). My question: Is it ok to use Purevison as a regular lense? i.e. I can use normal Renu multipurpose solution to store them overnight?
My other question is: What's the difference between omafilcon A and balafilcon A?
Yes, Purevision (and PV Toric) can be used as a 'daily wear' lens, i.e. take it out every night, clean it, etc. Some people have some solution issues when they do this -- certain solutions with these lenses can cause irritated eyes, so your eye doctor may give you a different solution -- but other than that, there's nothing wrong with doing this. You'll also need to check with your eye doctor that your eyes are healthy enough to wear any lenses overnight -- Purevision aren't the only ones approved for that.
And the difference between omafilcon and balafilcon? Omafilcon is a 'conventional' lens material, used for conventional ('regular', as you put it) lenses. Balafilcon is one of a newer class of materials called Silicon Hydrogels. This material allows a lot more oxygen to reach the eye, which is why it's okay to sleep in them. It's more of a technical difference, but you might find the Purevision (balafilcon) lenses a little 'stiffer' when you're handling them and trying to put them in and out. If I remember correctly, all the extended-wear/overnight-wear lenses are some variation of a silicon hydrogel material.