"Mr Heck Tate sat looking intently at Boo through his horn-rimmed glasses."
horn-rimmed glasses
Public Domainhorn-rimmed glasses - Credit: flickr.com
Horn-rimmed glasses are made of horn, tortoise shell, or plastic that simulates these materials. These glasses began to be popular in the United States in the 1910s and 1920s. Today, these glasses are typically dark, plastic eyeglasses with a frame that can be thick or thin.