The eyeglass lens prescription that you receive from your eye doctor will include an expiration date. The expiration date is the last day that you can use the prescription to buy new eyeglasses or replacement lenses.

According to the Federal Trade Commission (FTC), eye care professionals in the United States are required by law to give you a copy of your eyeglass prescription at the conclusion of your eye exam, even if you don’t ask for it.

Also, your eye doctor cannot require you to pay an extra fee for your glasses prescription — writing and giving you the prescription is considered part of the eye exam.

Your doctor also cannot require that you purchase your eyeglasses where you have your eyes examined or make you sign any sort of form that waives any of your rights associated with your glasses prescription.

Glasses prescriptions have expiration dates for good reason: Your eyes can change over time, causing your current prescription to become inaccurate and no longer adequately correct your vision. Eyeglasses made with an out-of-date, inaccurate prescription can cause eye strain, headaches, and possibly a serious accident due to blurry vision.

Even if your glasses prescription stays the same from exam to exam, you should have routine eye exams to make sure you're not developing potentially sight-threatening eye conditions like glaucoma, diabetic eye disease or macular degeneration.