Bifocals noun – Eyeglasses having two focal lengths, one for near vision and the other for far vision. Glasses and bifocals are semantically related in eyeglasses topic. In some cases you can use "Glasses" instead a noun "Bifocals".
Glasses noun – Optical instrument consisting of a frame that holds a pair of lenses for correcting defective vision. Bifocals and glasses are semantically related in object worn to correct vision topic. You can use "Bifocals" instead a noun "Glasses". popular alternative