iPhones and iPads are excellent devices for both low vision and totally blind users and have many in-built accessibility features. If you need to make phone calls, then you will need an iPhone; iPads can make phone calls, but only if the user's iPhone is nearby. Although Apple does sell Wi-Fi plus Cellular iPad models in which a SIM can be installed, the SIM is used only for a data connection when Wi-Fi isn't available. That will allow you to make FaceTime calls and maybe use some other data-based calling services when you are away from Wi-Fi but won't let you use the SIM in the iPad to make conventional phone calls. The most significant choice factor for most people with low vision is the screen size and they may prefer the larger iPad screen or the larger iPhone models and they will probably choose to use accessibility settings to enlarge text and perhaps change screen colours. People with more severe sight loss who can't easily read the screen may prefer the smaller and more portable iPhone. People with severe sight loss will only be able to use iPhones and iPads if they make a significant effort to learn VoiceOver and using VoiceOver isn't going to be suitable for everyone. See my page on selecting an iPhone for people with sight loss for more information.
last updated 28 December 2025