Why does Contact Lens Solution Evaporate Overnight?

It has been observed that contact lens solution sometimes evaporate overnight in contact lens cases and sometimes it takes a bit longer; but sooner or later the solution has to evaporate.

A research study was conducted by Abbot Medical Optics in 2009 which revealed that on evaporation of contact lens solution; many people fail to use fresh contact lens solution after each use. Instead; they prefer “topping off” the multi-purpose solution. Topping off contact lens solution is associated with several eye infections & hence is never recommended. It is better to be safe than sorry.

Reasons of Contact Lens Solution Evaporation:

The contact lens solution evaporates because of dry climate and lower levels of humidity. Moreover; the air conditioning may also facilitate quick evaporation. This is why you get dry eyes whilst wearing contact lenses in an air-conditioned building. It is always a good idea to lubricate and re-lubricate your eyes when dryness is noticed at wearing contact lenses.
What to do to Prevent Evaporation of Contact Lens Solution?

To prevent evaporation of contact lens solution it is advised to keep your contact lens cases

Enclosed in a zipper bag. This way you ensure to create a barrier between your lens case and direct open atmosphere. When the cases are not properly capped or are lying in an open atmosphere; the lower humidity levels and hot or dry temperature dries off the solution from cases.
If you cannot arrange a zipper bag; prevent evaporation by keeping your contact lens cases protected in a lens kit. It also helps preventing direct exposure of contact lens cases to the climatic changes.

There is a huge chance of contact lens ripping when they turn dry. Do not reuse dried-out contact lenses since it contains risks of corneal abrasions and scratches. Use a quality multipurpose disinfectant to rub, cleanse and disinfect your contact lenses. After every use please discard the previously used solution in cases and fill the chambers with fresh solution every night/morning. (Whatever your cleaning/disinfecting routine is)

Source: http://uniqsoblog.blogspot.com/2014/04/why-does-contact-lens-solution.html