Can I use contact lens solution on Shabbos and Yom Tov?
According to many poskim, contact lenses should not be soaked in a solution that will clean the lens from proteins etc, that get absorbed inside them, as it may be Mileches Melabein. However they may be soaked before Shabbos in the cleansing solution, and on Shabbos itself in plain saline solution.
This is only for soft lenses. Hard lenses may be soaked in contact lens solution.on Shabbos.
Kovetz Teshuvos ( R’ Eliyashev ZT”L) 1- 26, Orchos Shabbos 13-10,