This post is dedicated to the beginner on toric contact lenses or to learn more about:
- What toric lenses are and how they function
- How to know if you need toric contact lenses, also for children and dry eyes
- How to read a toric lenses contact lens prescription
- Disadvantages and risks of toric lenses, toric silicone lenses (extended wear)
- Comparing various toric lens types
- Cleaning and care for toric lenses
- Travelling with toric lenses, what is good to keep in mind
- Advice on where to find toric lenses on the Internet at discount prices
Toric lenses correct astigmatism which is a refractive visual defect. Astigmatism occurs due to a defective shape of the lens inside the eye, or more usual is a de-shaped cornea. Instead of a circular shape it assumes an oval shape which causes the light to break incorrectly on the retina.
Both children and adults must obtain a prescription and fit of their lenses to know what kind of size and material that is required for the lens. This is also the case for dry eyes. Identify a prescription for astigmatism by finding the base curve (BC), axis (AXIS), cylinder (CYL), diameter (DIA) on your paperwork from the optician (along with other information). Often the name of the toric lens is mentioned in the paperwork, but this is not always the case. Therefore, if you have been supplied with trial lenses, always check the package rather than the paperwork. In a prescription for spectacles, base curve and diameter will be missing, so be careful not to confuse the two different prescriptions! It is common to need correction for a very mild astigmatism for glasses, without needing it at all for contact lenses. It is less common to need astigmatism correction for both glasses and contact lenses.
There are several toric silicone lenses that are sometimes fitted as continuous wear or extended wear which means you can sleep with them for up to one month, depending on what the optician has recommended. Biofinity Toric are popular around the clock toric lenses, produced by CooperVision. Another well-established toric 24 hour lens is PureVision Toric from Bausch & Lomb with a successor called Purevision2 for astigmatism. Additionally, Ciba Vision Air optix for astigmatism and Johnson & Johnson Acuvue Oasys for astigmatism are two other popular lenses that are sometimes fitted as extended wear. There are discussions about continuous wear and the potential effects. In United Kingdom, it is quite common to use lenses for up to 30 days without removing them for cleaning, while in other countries such as France, the same type of lenses are prohibited. According to the French, there are no scientifically strong evidence that clearly proves that extended wear lenses are harmless. As always, be sure to consult with your optician for individual suitability before using a lens, this also goes for wearing schedules.
There is no lens that is “best in test” and fits all, but some manufacturers have chosen to historically invest in the production of toric lenses and are worth keeping an eye on. CooperVision manufactures a number of other contact lenses, but is particularly specialized in toric corrective lenses for astigmatism. They early produced a unique toric monthly lens called Proclear Toric that later also came in an XR version (extended range) with higher cylinders than most other lenses (up to -5.75), which is invaluable for those with severe visual defects. Historically, CooperVision Biomedics Toric have also been widely used and more recently released in a daily version. For toric daily disposable contacts, there is a more limited selection for correction of mild astigmatism. Johnson & Johnson released 1 Day Acuvue moist for astigmatism where the maximum cylinder is -2.25. Ciba Vision produces Focus Dailies Toric which is a very popular daily toric lens and available in larger packaging which is handy if you plan to buy torics in bulk.
Expiry date should always be marked on the packaging of toric lenses and on the lens container / blister. A rule of thumb is, the lower the water content, the sturdier and easier to handle the lens. Often, however, this will compromise comfort. More water in a lens presents a fragile lens that is more comfortable, but also thinner and more difficult to handle thus therefore breaks and tears more easily. For toric lenses with high water content, a lens applicator/remover can simplify handling. Durability of a lens is important, but more important is to get toric lenses fitted properly by an optician, because individual needs means that comfort and suitability for a type of lens can vary greatly from one person to another.
Proper cleaning and caring for toric lenses is important to ensure durability of the lens and avoid nasty eye infections. Tap water contains bacteria that can cause eye infections (avoid fruit juice as well, for that matter), so instead only use fluids designed for eyes when you clean your lenses. If you do not take care of your contact lenses properly or do not bother to consult your optometrist for a fitting, you may experience discomfort, the lenses can tear or you get dry eyes.
If you are traveling you can bring toric lenses, but since the packaging contains liquid it is recommended to put the lenses in a transparent plastic bag within the EU, where no more than 100 ml of liquid is allowed to bring along. Always read instructions before you travel as the rules and laws can change. You may as well buy a travel-friendly flight pack contact lens solution.
There are no lenses designed for only the left eye or right eye. A lens is a piece of plastic with prescription inside. In essence, you can buy two (or more) packages for “two eyes” but choose the same strength on both and just use all the lenses in your left eye, for example. You can find toric lenses at excellent prices online with fast delivery at Visiondirect.co.uk. If you have any questions regarding prices or toric lenses, please feel free to contact us.