every 30 days? and change the lens case?
i wear ones from the BSS (beauty supply store)

Well first off, what kind of contacts do u wear? Are they disposable? l wear contacts & have for 25 years & l toss mine after 2 weeks. As far as the case for the lenses, as long as u clean it with hot soapy water, rinse it well & let it air dry u do not need to throw that away. But to reduce eye damage, never sleep with ur contacts in, even if they say u can (trust me l almost had to stop wearing them due to this)
Contacts r mostly made of water & they do break down & accumulate protein deposits that r not good for ur eyes, that is why new, fresh pairs r necessary.

because contacts get dirty and can cause eye infection. also did you know you are supposed to have an contact lens exam to wear the proper contacts. even if they are cosmetic and have no prescription. you must get fitted for them. contact bought at a beauty supply are not fitted and can scratch your cornea.