Airport security regulations currently consider contact lens solutions, saline solution, and rewetting drops as "over-the-counter medications" that can be carried on the plane if they meet the following inspection criteria.
All prescription and over-the-counter medications (liquids, gels, and aerosols) including lubricating jelly, eye drops, and saline solution for medical purposes are permitted. You are not limited in the amount or volume of these items you may bring in your carry-on baggage. BUT if the medically necessary items exceed three ounces or are not contained in a one-quart, zip-top plastic bag, you MUST declare to one of the security officers at the checkpoint for further inspection.
For further information and updates on security regulations for the US and other countries that have adopted the Transportation Security Administration (TSA) guidelines, check the TSA Web site at:
http://www.tsa.gov/travelers/airtravel/specialneeds/editorial_1059.shtm