Contact lenses come seal-packed in the sterile saline solution. Saline solution is basically salt water which has a freezing point much lower than water. Usually, it is rare for the contact lens solution to get frozen, but if it does it will also turn your contact lenses solid. Contact lenses however, can be allowed to thaw. Inspection is mandatory before using them again.
Contact Lenses during Shipment
If you order contact lenses online, your package moves from warmer regions to colder regions. Though the shipper secure the vials, pocketed in warm bubble-wrap envelops to prevent freezing, sometimes the fiercely low temperatures set everything out of control. In case, you find your contact lenses shriveled and your solution frozen upon receiving a package, allow it to thaw on room temperature. Please remember that room should be well-heated. If you mistakenly abandon your package in a room or building that is not currently in use, and has a temperature lower than -20 degrees; your contact lenses are subjected to get completely frozen.
What to do when camping?
Courtesy: Scout Backpacking Community
Camping is a genuine concern. We can control indoor temperatures, but outside it may be way too cold. Outdoor weather can be unpredictable sometimes. If it suddenly turns harsh and you are being concerned about your contact lenses then let us tell guide you. Insert these contact lenses in eyes if you are not already wearing a pair. Body temperature will keep contact lenses from freezing. On the other hand, if it is your spare pair of contact lenses; then try rubbing them in your palms. It might be tedious if you have already broken the seals of the vials and transferred the lenses in the cases. However, friction will eventually help thawing your contacts. At sleeping, ensure you keep your cases close to your body such as in your sleeping case to keep them warm.
It is advised to use re-wetting drops as in colder climate your eyes may turn dry quickly. Low rate of oxygen at higher altitudes can be held accountable for the dryness. Though thawing should help your contactlenses get back to their shape, it is necessary that you inspect your lenses closely. Do not try to touch your crumpled lenses or else they will not remain usable.