I know there is debate as to whether it is okay to soak contacts in disinfecting solution (vs. plain saline) on Shabbat. However, if one puts them in to soak before Shabbat (e.g., 12 pm Friday) and then does not touch them again until after Shabbat ends, is that permitted? (or becuse they are still being soaked and maybe cleaned–even if one is not actively doing anything during Shabbat–it is still prohibited?)
As long as you are not placing it into the saline solution on Shabbos it is permitted. The reason being is that we can do melacha before Shabbos begins even though the effect of the melacha will only take place on Shabbos itself. For example, lighting a candle before Shabbos, which will burn into Shabbos, or placing uncooked food (on a blech) before Shabbos.
Shabbos 17, O:CH 252-1.