If you’re not an expert in the optometry field, it can be very difficult to understand the in and outs of what types of eyeglass lenses are available. As such, you should definitely rely on your optometrist and his staff for guidance. With that said, being an informed consumer always makes sense. Therefore, we’ve taken a plain-spoken approach to explaining the major types of lenses and what they are used to treat.
Single Vision
The first type of lens that we will discuss is single vision. These are used to correct myopia and hyperiopia. In layman’s terms these refer to farsighted (hyperiopia) and nearsighted (myopia). Each of these diagnoses is exactly how their name describes them. That is, a farsighted person can see far away but not as well close up and vice versa for a nearsighted individual. Glasses with either type of lens are made to correct only one field of vision, meaning that the strength is consistent throughout.
Bi Focals
Unfortunately, some individuals have difficulty seeing close up as well as far away. Luckily, there is a solution. Bi-focals essentially have two prescriptions in one. The glasses are divided so the upper portion is used to see further away while the lower portion is for tasks like reading. The lower portion helps those with a diagnosis of presbyopia, which means the patient has difficulty focusing on items that are close by.
Tri-Focals
Naturally, like most things in life, vision isn’t cut and dry. After all, exactly how far away is distance vision and how close is near vision. Thankfully, experts realized that there is an in-between area that many have trouble with and have developed tri-focals to address this need. These types of lenses simply have an added area for intermediate viewing just above the close viewing area in a bi-focal. The result is increased vision at distances in the 18 to 24 inch range. These are great options for those who have to view computer monitors or vehicle speedometers throughout the day.
Progressive
To the excitement of eyeglass wearers, there is one more very popular type of lens. The progressive lens works much like tri-focals but the lines that divide the near, intermediate, and far vision areas are smoothed. This leads to a more seamless transition from one area to another for the wearer’s eyes. This type of lens is also a favorite because the hidden lines mean it’s difficult to tell that you’re wearing tri-focals. At a glance, they look like single vision glasses.
In closing, understanding prescription eyeglass lenses and the conditions they treat can be fairly simple concepts. Once the medical jargon is taken away it’s a simple matter of matching a lens type with the eyesight constraints you are experiencing. Hopefully, this guide can help you be more informed the next time you speak with your doctor.