One thing that occured to me this morning, maybe a small bottle of eye drops? If you wear contacts, you know that if something happens, there'll be dust and everything just to make things difficult. Alternately, carry a contact lens case, prefilled with saline. You can have some solution/eye drops and spare glasses in your larger bag. This allows you to take out the troublesome contact, or rinse it and put it back in. Walking/driving with 1 contact in is kind of a hassle, but doable.