How long an eyeglass prescription is valid depends on the state you’re in, not on federal law. Most states cap validity at two years, but the full range runs from about 18 months to five years, and a few states set no limit at all, leaving the expiration date entirely to your eye doctor. The date printed on your prescription is the one that governs in practice.
State Law Sets the Expiration, Not Federal Law
There is no federal expiration date for eyeglass prescriptions. The FTC’s Eyeglass Rule protects your right to receive a copy of your prescription, but it deliberately does not set a validity period.1Federal Register. Ophthalmic Practice Rules (Eyeglass Rule) That call is left to state legislatures, and they don’t agree.
Two years is the most common state-mandated maximum. In many states it functions as a hard ceiling: your eye doctor can shorten the expiration based on your health, but cannot extend it past two years. Other states run more generous or more restrictive. A handful allow prescriptions to remain valid for three to five years. At least one caps validity at 18 months. Several have no rule at all, meaning whatever expiration your prescriber writes is the only limit.
Because the rules vary so much, the expiration date printed on your prescription is what matters for practical purposes. If you move, a prescription that was valid where it was written may not be honored where you now live. When you aren’t sure, call the optical shop where you plan to order and ask whether they’ll fill a prescription with your specific expiration date.
Contact Lenses Are on a Different Clock
If you wear both, don’t assume the same expiration applies. Contact lens prescriptions have a federal floor: they must remain valid for at least one year from the date written, and states can extend that period but cannot shorten it below one year.2eCFR. 16 CFR 315.6 – Expiration of Contact Lens Prescriptions A prescriber can set a shorter period only for documented medical reasons that go in your chart.
Your eyeglass prescription and contact lens prescription are also not interchangeable. The measurements differ, and an optical shop cannot use one to fill the other.
When You Should Get Re-examined Sooner
Even if your state gives you the full two years, your vision can outpace the calendar. Several situations make an earlier exam worth scheduling rather than waiting for the paper date.
- Children under 18. Kids’ eyes change quickly, and pediatric optometrists and ophthalmologists often set shorter expirations, sometimes as brief as six months for younger children, because a prescription that was accurate in September can be meaningfully wrong by spring.
- Adults over 40. Presbyopia, the gradual loss of near-focus ability, accelerates through your 40s and 50s. If you’ve recently started needing reading glasses or bifocals, the “add” power may need updating more often than the rest of your prescription.
- Diabetes or high blood pressure. Both can change the shape and fluid dynamics of the eye, shifting your prescription unpredictably. Diabetic retinopathy in particular can progress without obvious symptoms until it causes real damage.
- Sudden vision changes. New blurriness, double vision, halos around lights, or persistent headaches are reasons to get examined now rather than at your next scheduled visit.
Why Filling an Expired Prescription Isn’t an Option
An expired prescription is not just a technicality. Opticians and online retailers are generally prohibited from filling one, so you’ll need a current exam before you can order new glasses. That catches people off guard when a pair breaks and they assume they can just reorder.
Wearing glasses built to an outdated prescription forces your eyes to compensate for the mismatch. The usual result is eye strain and headaches that get blamed on screens or stress rather than the lenses. For children, an incorrect prescription during key developmental years can contribute to worsening refractive errors instead of correcting them.
The less obvious reason expiration dates matter is what happens during the exam itself. Routine eye exams catch early signs of glaucoma, macular degeneration, cataracts, and systemic diseases like diabetes. These conditions often produce no symptoms until they’ve already caused damage. The prescription expiration works as a built-in reminder to get screened.
Getting a Copy of Your Prescription
Federal law requires your eye doctor to hand you a copy of your eyeglass prescription at the end of your exam, automatically, whether you ask for it or not, and without charging an extra fee.3Federal Trade Commission. Complying with the Eyeglass Rule The doctor must give it to you before offering to sell you glasses. That’s the FTC’s Eyeglass Rule, and its purpose is making sure you can shop wherever you want: your doctor’s office, a retail chain, or an online retailer.
Your doctor cannot require you to buy glasses from them as a condition of getting the prescription. They cannot make you sign a waiver, pay a separate “prescription release” fee, or sit through a sales pitch before handing it over.3Federal Trade Commission. Complying with the Eyeglass Rule If any of that happens, report it to the FTC at ReportFraud.ftc.gov.4Federal Trade Commission. Buying Prescription Glasses or Contact Lenses: Your Rights
If you’re within your prescription’s validity window and want to reorder, you have the right to that document. If you’re past the date on the form, no retailer can fill it, and the next step is an exam.