Absolutely you can not. You may think there is no harm in adding some new contact lens solution to the old solution in your lens case, but you would be wrong. That would cause the disinfectant to lose its effectiveness. Moreover, the old solution must be infected with some bacteria coming from your used contacts. In that way, the mixture will put you at risk for serious infection. So changing the solution every day is the wise decision.
No, you can not. multipurpose contact lens solutions require that after you have manually cleaned the lens, you must store it in a clean contact lens case and fill it with saline-based disinfecting solution. Some wearers, to avoid spending more money on contact lens solution, simply top off the old solution after cleaning them again the next day. The chemical agent that disinfects the contact lens loses its potency if not completely replenished with a fresh batch of solution. Bacteria, viruses, fungus and amoebas may not be killed, and are allowed to flourish in that little petri dish.
No you can't do like that, because the old contacts solution contain some harmful bacteria that will cause a potential eye infection. Of the 1,000 contact wearers polled for a recent research, 96 percent admitted to frequently reusing or topping off old solution. When a contact sits and soaks in solution, the mixture becomes depleted of its organism-killing biocide, rendering it ineffective for disinfecting your lenses, so you had better Opt for only fresh solution with every use.