• Finding the right glasses can make your life easier.Kazuhiro Tanda/Digital Vision/Getty Images
  
  Having bifocals allows you to wear your glasses all the time when you require different adjustments for near and far. Bifocals elminate the need to remove or switch glasses when changing between closeup and distance viewing. There are multiple styles of bifocal lenses available.
  
  

Flat-top Bifocal

• Flat-top bifocal zones offer a square towards the bottom, inside area of the lenses. This type of lens is also known as a half-moon or D-segment lens. These lenses work well if you read often, but need no correction for distance. The glasses can also be fitted inside a lens that adjusts distance vision.
  
  

Round-Segment Lenses

• A round-segment lens still has a line, but is often considered preferable because the line is not as noticeable on the lens itself. The rounded portion is on the lower-half, inner-section of the lens and serves the same purpose as the flat-top bifocal. The area of the rounded section is smaller, so it sometimes takes more time to get used to. Once you do, though, the lens is less bothersome during other tasks. If you intend to wear your glasses when walking long distances, this lens is more likely to help you avoid vertigo.
  
  

Executive-style Bifocals

• Executive-style bifocals adjust the entire lower half of the lens. These are for people who spend much of their time sitting at a desk reading. They allow for you to look up across the room or at a computer, but require less specification for your eyes when you read. You are not likely to move your eyes outside of the corrective region when reading because there is no edge to the lens. These glasses are not recommended for wearing while moving, as you are likely to feel uncomfortable when walking. They can cause vertigo or make you feel slightly "seasick."
  
  

Golf Bifocal Lenses

• Golf bifocals offer a rounded corrective zone on the bottom, outside segment of the lens. The name explains the purpose: the placement works well for playing golf. It allows a golfer to focus on the ball when looking down, but to also keep track of the ball on its way toward the hole.