I brought up a similar dilemma a while back, received a lot of advice, and it really depends on whether you're willing to bend the rules a bit. The law in some states is that you have a year (or, from what I've read here) two years to renew an expired license without having to take the test again. If you're applying for renewal in a state where you must go to the DMV to do so if your license has expired, and that license had your U.S. address on it, tell the DMV/MVA person (if he/she asks) that the address on your license is still valid (if you say your address has changed, they'll want to see a couple of bills in your name, addressed to you at your new address in the state, to prove residence). If you play your letting your license expire off as an oversight, you shouldn't have a problem... Some on here will say, "That's not fair if you don't still live there." To them I'd say, "What's the big deal? Who WOULDN'T want to be licensed to drive when they're in the States?" Also, regardless of whether or not you have a restriction on your license that you must wear glasses while driving, if your vision is questionable, bring glasses with you, because you'll inevitably have to take the vision/eye test again. If you fail it, you'll have to go to an optometrist, get glasses, and go back and pass the vision test before they'll renew the license.
P.S. For the Brits on here wondering what the hell we're talking about, in the U.S. all states require that your driver's license be renewed every four to five years, and most (I thought all) licenses require a photo on them. I was amazed when Andrew showed me his paper license and said that in the UK, you don't need to renew your license and no picture is required (although I think the law is going to change about that). That seems like a prime possibility for identity theft, right there. If your license is lost or stolen in the States, most DMVs/MVAs (Departments of Motor Vehicles/Motor Vehicle Administrations--same thing) require that you show them your birth certificate or a certified copy of it, your Social Security card, and/or other items that verify you are who you claim you are before they'll issue a replacement. Also, in general, you won't meet anyone who doesn't think their driver's license picture is hideous--it's similar to a mugshot, but less flattering.