There are various types of bifocal lenses available in the market, such as: 1. Flat-top bifocals: These lenses have a visible line separating the distance and near prescription. They have a larger distance portion and a smaller near portion. 2. Round segment bifocals: Also known as "seg" or "golf" bifocals, they have a small, round portion at the bottom of the lens for near vision. 3. Executive bifocals: These lenses have a larger near portion for reading and a smaller intermediate portion for computer work. 4. Occupational bifocals: These lenses are designed for specific work activities and have different prescription powers in different areas of the lens. 5. Progressive bifocals: These lenses offer a smooth transition between the distance and near prescriptions, without any visible line.