Eye Health Central

High Power Prescriptions

What Are The Best Contact Lenses for High Power Prescriptions?

Thick GlassesPeople with extreme vision prescriptions sometimes assume contacts can’t be strong enough for their eyes. You’d be surprised, however, how far contact lens design has advanced in recent years. 

Sure, eyeglasses can still correct greater degrees of refractive error, but most myopia, presbyopia, and astigmatism patients fall well within the powers that contact lenses can correct. Just because you have a strong refractive error doesn’t mean you should put off wearing contact lenses.

While they might not be as comfortable as other contact lenses, high-powered lenses are certainly available to purchase. Below, we’ll go over a few things to consider about wearing stronger powered contacts. 

Contacts Versus Eyeglasses: Not Created Equally 

Before we get into the particulars of high-powered contacts, it’s important for patients to realise that visual prescriptions for eyeglasses are very different from contact lenses. So, if you order a pair of contacts with an eyeglass prescription, your new lenses won’t correct your vision. 

The reason this is so is quite simple: contacts are a whole lot closer to your eyes than eyeglasses. Optometrists factor in the distance of your glasses from your eyes and adjust this for contact lenses, which are of course placed on your eyes, when gauging your contact lens refractive power. The higher the power of your glasses, the greater the discrepancy bewteen your spectacle power and your contact lens power. 

In addition to different refractive powers, contact lens prescriptions contain detailed information related to your lens fitting. These fitting numbers are extremely important because improperly fitted lenses could cause significant eye discomfort and blurring.

If you have any questions about your lens prescription, please don’t hesitate to ask your Optometrist on your next visit. It’s also a good idea to ask for a copy of your most up-to-date prescription for safekeeping.

Many people are surprised to learn that contact lenses can be prescribed for very high degrees of myopia, even for people who are require correction of more than - 20 Diopters. In particular vial lenses can go over -30 Dioptres. It is advisable to get these high powered lenses properly fitted by the Optometrist.

People who have high power prescriptions are familiar with their first set of thick eyeglasses and have hunted down the thinnest lenses possible but may still want to try out contact lenses or at least have them for some occasions.

The highest level of corrective power for monthly soft contact lenses is about -12 Dioptres (bear in mind that the average prescription for short sighted people is -2.00 Dioptres), and is available from both Purevision 2HD and Biofinity.

For people with astigmatism, who require toric lenses, the maximum is about -9 Dioptres of sphere. These are also available from Pure Vision 2 HD Astigmatism, and Biofinity Toric.

Are High Power Prescription Contact Lenses Comfortable?

It's important to know that high powered soft contact lenses are a bit thicker at the edge than low powered ones, and are more likely to be felt while wearing them. Even so, they are comfortable enough for most people who choose to wear them. Because they are thicker, they are also more likely to contribute to dry eyes as the soft hydrogel material the lens is comprised of can wick away moisture from the surface of the eye. This can also negatively affect the oxygen permeability of the lens.

For these reasons, some people who wear high powered contact lenses experience eye fatigue or irritation after wearing the lenses for more than 12 hours. However, soft contact lenses like the Purevision 2HD, which is an extended wear lens and available in short sighted powers up to -12D, can be worn on a daily wear basis (up to 12 hours), allowing a lot of oxygen to pass through the material to the eye, keeping them comfortable through the day.

People who have been diagnosed with dry eye syndrome are most prone to the negative side effects of wearing high-powered contacts. This doesn’t mean, however, you can’t wear high-powered lenses if you suffer dry eyes. Simply ask your optometrist if s/he recommends a particular brand of silicone hydrogel contacts. 

In recent years, silicone hydrogel has shown promise in increasing the amount of oxygen able to reach the corneas. This increased oxygen permeability could help reduce symptoms such as eye itchiness, redness, and discomfort.  Silcone containing contact lenses are almost always recommended for higher prescriptions by Optometrists to increase the oxygen flow through the thicker parts of the lens, resulting in healthier eyes long term. 

Rigid Gas Permeable (RGP) Lenses for High Power Prescriptions

RGP lenses are smaller, thinner, more oxygen permeable, and do not absorb moisture from the surface of the eye. Many people with high power prescriptions may choose RGP lenses over soft contacts. Although, since RGP lenses don't conform to the shape of your eye the way soft lenses do, they usually take some time to get used to. It is possible to correct in excess of 20 dioptres of shortsightedness using gas permeable lenses.

Other benefits of RGP lenses include their enhanced durability, ability to keep off protein deposits, and long shelf life. Indeed, it’s not unheard of for patients to use one pair of RGP lenses for one year. 

So, what’s the catch? Well, RGP lenses aren’t so hot in the comfort department. Some people simply find it impossible to adapt to the rigid feel of these contacts. RGP contacts also tend to fall out easily, especially if wearers are involved in high-intensity sports.   

Got More Questions? Check Out Our Portfolio

If you’re looking for a high-prescription pair of contacts, please check out our extensive range of lenses. You’ll find a wide array of daily, 2 weekly, monthly, and even continuous contact lenses to choose from on our website. We are also proud to offer fun cosmetic contact lenses as well as many secondary eye care items like all-in-one disinfectant solutions, contacts lens cases, and sunglasses. Click on this link to check out all the products in our website.


Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 6 Sep 2016, Last modified: 28 Mar 2020