Should I (not) wear this pair of contact lenses?

I have a pair of red cosmetic contact lenses; I haven't put them on since early 2014 (I have just worn them 3 times, ever; and I haven't had vision problems afterwards). They have always been in contact solution in individual cylindrical cases. I have to say I change the solution sporadically, not so often…, but I wanna wear them again, more often. Do you think I should not do it? Or can I use them as long as they are in solution? (also, should I use the solution to clean them?) (They don't seem to be broken, they look the same way they did when I got them). Thanks in advance!
Added (1). Or you could also answer this: How long can a pair of cosmetic contact lenses last or be used for? (generally) and does the frequency you use them at have to do with them being no longer usable?

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