Products
Contact Lens for Astigmatism
You may have heard of toric contact lenses for astigmatism, but first, what do you know about the term “astigmatism”?
Astigmatism exists when the clear front window of the eye, the cornea, is shaped like a rugby ball rather than a round basketball. When light passes through the cornea, instead of forming one single image, multiple images are formed at the retina.
A small amount of astigmatism is commonly found in most people, which can be neutralized easily with simple contact lenses. Toric contact lenses are used for a more moderate amount of astigmatism, providing a clearer vision during contact lens wear.
Standard contact lenses have spherical surfaces, imagine them like a slice of a round ball. While toric lenses on the other hand, are shaped in a particular way in which the focusing power is different between vertical and horizontal orientations, now you can think of slicing the side of a donut.
This particular design in toric contact lenses allows the correction of varying focusing power in different meridians which is found in astigmatic eyes.
Contact Lens for Astigmatism
Toric contact lenses are often thicker at the bottom to keep the lenses from rotating (frequent lens rotation causes unstable vision), while others rely on thin zones that interact with the eyelids to maintain stability, some however, use a combination of both.
Toric contact lenses are more complex to design and manufacture, which makes them more expensive than the standard non-toric lenses, even from the same manufacturer.
Besides, there is a variety of toric lenses in the market. Aside from monthly disposable toric lenses, many people opt for daily disposable toric lenses for convenience. Undoubtedly, many daily lens wearers can tell how much hassles they are able to save in their daily lives.
What do we consider during the selection of toric contact lenses?
- Power Range
In the current market, toric contact lenses cover a specific range of astigmatic powers. It is hence vital for us to carefully consider your astigmatism first. Manufacturers like Johnson & Johnson, CooperVision and Alcon do cover higher astigmatism of -2.25DC in their respective range of 1 Day Acuvue Moist (Astigmatism), Acuvue Oasys (Astigmatism), Clariti 1 Day Toric, Biofinity Toric and Air Optix (Astigmatism). For those who have astigmatism higher than that e.g. -2.75DC, Acuvue Oasys (Astigmatism) might be the only option. Good news for those who have lower astigmatism, as the power range could be covered by most toric lens manufacturers!
2. Replacement Module
What are the occasion you wish to wear toric lenses? “Only for events like wedding dinner or occasional gathering.” We recommend daily lenses. “For work 8am-6pm.” Monthly lenses can be suitable. While this is just a rough idea on how we select the lens replacement module for you, it can still vary depending on your eye or workplace condition. So, tell us more about you!
3. Size
Yupe, you hear it right! Toric lenses come in different sizes too. Here, we are talking about the lens diameter and base curve. There are diameters like 14.0mm, 14.2mm or even 14.5mm while base curves are available from 8.5 to 8.9, these parameters are crucial in determining a perfect fitting, which is why a thorough contact lens assessment is needed beforehand to ensure optimal comfort and health.
4. Material
Silicone Hydrogel is known to make your cornea breathable during lens wear, which is crucial if you need to wear the lenses for a longer period of time. Hydrogel on the other hand, ensures your wearing comfort, thanks to the thinner texture and high water content. It comes to the question, which one should you go for? Not only your corneal health should be thoroughly inspected in terms of tear count and corneal shape, but your wearing occasion as well as duration, too!
As every eye with astigmatism is unique, it can take more than one pair of toric lenses in order to get the design that provides the best fit and wearing comfort, as well as giving you the most optimal vision.
How to know if a pair of toric lenses fit your eyes?
Therefore, fitting toric contact lenses is especially critical, it takes more expertise as compared to fitting non-toric lenses. When the contact lenses are able to optimally move across your cornea and effectively allow tears exchange while giving you the best vision, you have successfully achieved an optimal fit!
To know whether you need a pair of toric lenses, talk to us about your lifestyle and when you will be the most in need of improved vision! This may go a long way towards determining the best lens type for you. Feel free to consult our optometrists for more!