Replace the lenses often enough
Each lens is different, but you must follow the suggested instructions faithfully.
We understand, they are not cheap, and you may want to keep them a little longer.
But if you keep your monthly lenses for three months then they are probably full of microorganisms and not oxygenated enough.
And one more thing: you have to replace them on time regardless of the use you made. Even if you wore them 10 times a month they should be changed.