Most polling places are accessible, and will have at least one accessible voting machine, including one that can be used by voters with a visual impairment. It must also be wheelchair accessible and enable a private vote.
If your polling place is not accessible, you can contact your local election official for assistance with finding accessible voting options. Some jurisdictions allow supervised voting in residential facilities. Many also have a service called curbside voting that allows elderly voters and voters with disabilities to vote from their vehicle. In some jurisdictions you can only use curbside voting if the polling place is physically inaccessible for you. In other locations, anyone with a disability can vote curbside. Some states do not allow curbside voting at all.
U.S. Vote Foundation has a state-specific Voters with Disabilities Guide. Simply select your state from the dropdown menu, and on the following page click on a tab to find information on accessible voting options.
If your elected official cannot provide you with an accessible voting option in your jurisdiction, you can file a complaint with your state or the Department of Justice.