Facebook improves alt text photo descriptions for blind, visually impaired users The feature can now recognize landmarks, activities and types of animals. Listen - 01:46 Facebook is providing more detailed image descriptions for blind and visually impaired users. Andrew Hoyle/CNET Facebook on Tuesday rolled out an update to its Automatic Alt Text (AAT) feature that improves the detail of photo descriptions for blind and visually impaired users. The tool, which launched in 2016, uses computer vision technology to automatically create descriptions. Updates are available when using a screen reader, an assistive technology that converts text to speech. An example of a detailed image description for a photo of five people playing musical instruments.