Rectangle glasses are particularly flattering on round and oval face shapes. The angular lines of the frames help to elongate and add definition to softer, more rounded facial features, creating a balanced and aesthetically pleasing look. For individuals with oval faces, rectangle glasses accentuate the face's natural symmetry, while for those with round faces, they introduce contrast, helping to make the face appear thinner and longer. However, the key to finding the perfect pair of glasses is considering personal style and comfort, along with face shape compatibility.