Do contact lenses have a expiry date?

You can but it is not advisable nor is it safe. After the expiration date, your contact lens solution may begin to degrade; how fast will depend on the brand and chemical components of the product you use.

This can mean that the pH level, which is optimal before the expiration date, will become unstable and likely more acidic. Irritation, itchy eyes, blurriness, and infection can occur with use of expired contact solution.

I accidently used a 2007 solution (the current date was late 2009) and found myself with extremely uncomfortable burning vision until I realized my mistake. Consult your eye doctor always for any personal advice like I did.