“I have a high glasses prescription and was wondering if there have been any advances in technology that will allow me to achieve better vision. It seems like my vision has always been distorted though glasses!” – Bob via email
You know, you’re in luck Bob because Vista Eye Care offers Shamir Digital lenses for those prescriptions with high astigmatism, high farsightedness, and high nearsightedness. Digital lens designs are available in single-vision glasses as well as progressive lenses. The idea behind digital technology is that it will allow you to see clearly through the entire lens. Conventional “spherical” lenses only permit perfect vision through the very center of the lens, and the quality of your vision will be reduced the further your eye looks away from the center of that lens (see Figure 1 which demonstrates the difference between a non-digital and a digital lens). Digital lenses will result in thinner lenses that provide clearer vision than can be achieved in non-digital designs. Couple the digital design with a high index lens material and a good anti-glare coating, and you will have the thinnest, clearest lenses available anywhere! Learn more about Shamir digital lenses here.
Figure 1 – The lens on the left represents the gradient zones of clarity in a high-powered single-vision lens. The area that is most clear is in white, and the yellow represents distortion. As the eye starts to look out of the peripheral portions of the lens, the visual acuity in that region gradually grows poorer. By contrast, on the right, a digital lens is designed specific to both the frame and the patient. This technology eliminates all distortion in the lens no matter where the eye looks.
“I have been saving up for LASIK, and now I’m curious if I’m a good candidate. Can you offer your advice?” – Heidi via email
There are several factors that make an eye a good LASIK or PRK candidate. Both of these surgeries are what are known as “corneal refractive surgeries” because the procedure alters only the curves on the clear front part of the eye (the “cornea”). As you may have suspected Heidi, a patient’s candidacy for these procedures really boils down to numbers.
The first number to consider is the patient’s glasses prescription. If a prescription is too farsighted or too nearsighted, that eye will probably not be a practical candidate for a surgery that involves flattening the cornea significantly. Astigmatism, when it is mild, is not generally an issue for corneal refractive surgery, though patients with high astigmatism may not be good candidates. It is also important to consider how the patient uses their eyes. If the goal of the procedure is to see well far away, then some patients will lose their ability to see comfortably up-close without glasses. Most patients getting LASIK or PRK are nearsighted which means that the focal point of their eye lies naturally close to that eye. If that focal point coincides with where they like to read or use the computer for example, then LASIK will affect their ability to read and work up-close. Maybe that is a trade-off that is worthwhile –many patients pursue LASIK to free themselves from having to wear vision correction when swimming, running, and driving, and they wouldn’t mind having to wear reading/computer glasses while working in the office. It is definitely worth discussing these points with our optometrists to determine just how your specific vision would be affected by these procedures.
Some prescriptions are too high for LASIK, but a similar surgery call “PRK” (photo-refractive keratectomy) might be a better option because it conserves more of the corneal thickness. Corneal thickness is the next number that we have to consider when deciding how well an eye would do that undergoes LASIK. A healthy cornea is generally about 500 millionths of a meter (500 microns) thick – pretty thin! For a cornea to endure a laser procedure, it has to have a certain starting thickness since the laser can only thin the cornea by removing corneal tissue. If the cornea is too thin, the predictability of the outcome is reduced, and corneal refractive surgery probably isn’t a good option. Keep in mind that a number of other, non-corneal refractive options exist, so even if you have a very high prescription, thin corneas, or both, there are still practical options to get you seeing great, and reduce your dependency on glasses.
The last number to consider in determining a patient’s LASIK candidacy is age. You don’t want to be too young when you have refractive surgery of any kind because your eyes are still developing. In those patients that pursue LASIK in their late teens or early twenties for example, they are often back to wearing distance correction within a few years because their eyes were still developing at the time that they had the procedure. If your glasses prescription is consistent year-to-year at your annual check-ups, it may be practical to have a refractive corneal procedure performed earlier than most patients, but we generally recommend most patients wait until their mid-twenties at which time their glasses prescription will have leveled out and remain stable.
At the other end of the age spectrum is an ocular disease called cataracts. Cataract surgery is something to consider because you can think of it as a refractive surgery in disguise. When a patient has cataract surgery, the internal lens of their eye is removed (an opacified lens is what constitutes a cataract) and replaced with an artificial (plastic) lens. That plastic lens is selected with a power that also incorporates the patient’s glasses prescription. Many times, having LASIK done before cataract surgery is a bit of a waste since the end result of a successful cataract surgery may be the same great vision achieved with LASIK.
Presbyopia is also important to consider because it affects vision when you are in your early forties. Presbyopia is the condition where the eye’s focusing ability is reduced. If you have perfect distance vision (either naturally, or as a result of contact lens wear or refractive surgery) you will need glasses to read up-close, probably around the age of forty (sooner if your occupation or hobbies involve lots of reading of computer use). You can certainly get LASIK or PRK in your late thirties or your forties, but you will likely need to wear reading and computer glasses after the procedure. So what is the ideal age for LASIK? Generally, your mid-twenties is perfect. Assuming you are a good candidate in general, if you have LASIK in your mid-twenties, you will likely enjoy 10-15 years of good vision at distance and near before your early forties kick in and you need to start wearing near-glasses.
Refractive surgery is a great option for many patients, though like any refractive surgery, it is a permanent alteration of the eye’s refractive power and you should consider how these procedures will affect your long-term vision. The side effects of the procedure should also be considered. Vista Eye Care is proud to work with the TLC Vision Center for our PRK and LASIK patients. TLC performs LASIK and PRK no-cost consultations at Vista Eye Care once per month. Please contact our office at (303) 450-2020 to schedule your LASIK consultation to learn if you would be a good candidate, or discuss LASIK and PRK with your eye doctor at your next annual check-up. Also, feel free to schedule your next annual eye and vision check-up online using the button below:
