Medical Device Nonvisual Accessibility Act of 2021 This bill requires certain medical devices with a digital interface to meet nonvisual accessibility standards established by the Food and Drug Administration (FDA). Specifically, the FDA must establish regulations to require a Class II or Class III medical device with a digital interface to provide a blind or low-vision user access to the same services and information, and generally the same ease of use, as provided to a user who is not low-vision or blind. (The FDA classifies medical devices in three classes. Class I devices are low-risk, Class II devices are moderate-risk, and Class III devices are high-risk.) A Class II or Class III medical device that does not meet the nonvisual accessibility standards established under this bill may not be sold.