That features a distinct design where the upper part of the affordable prescription sunglasses online mimics the appearance of eyebrows, while the lower part typically consists of thinner rims or is rimless. This style became popular in the 1950s and 1960s and has since maintained its classic and retro appeal. Browline sunglasses often have frames made of plastic or metal, with the upper part being thicker and more prominent than the lower part. The lenses are usually rectangular or slightly rounded, and the overall design aims to highlight the browline and add a sophisticated and intellectual touch to the wearer's appearance.