In Ohio, the registration period depends on your tier. Highest tier (can't remember if it's 3 > 2 > 1, or 1 > 2 > 3) has to check in with their local sherrif's office twice a year for life. Middle tier is twice a year for 25 years. Lowest is once a year for 10 years. After that period your name is removed from the registry and the restrictions are lifted (although your offense is obviously still on your record, so you'll get an even heavier punishment if you offend again).
There are also ways to get it reduced after your sentencing. My family member has spent the past 7 years in a state sponsored sex-abuse therapy program that involves both individual and group therapy aspects. He actually completed and graduated from the program about 6 months ago, but he's chosen to stay with the program voluntarily to continue with the group aspect as (in his words) "a way of reminding myself where I've been, and giving back to the community by helping others like me to change and not create more victims." Because he completed the program he'll be able to petition the judge to reduce his registry tier by one (from the middle, where he currently is, to the lowest) and would get him off the registry 15 years earlier than otherwise.
Well that's good, I've had friends who have been convicted sex offenders for what we'd all call completely harmless actions (Like turning 18 before your girlfriend, that kind of thing) and its good to know at least its not for life. There should be a way to make it even less than 10 years tho, cuz damn that's a long time for some innocent nonsense that is technically against the law. ---