There are many different types of contact lenses out there — dailies, monthlies, and coloured contacts, all of which are rather self-explanatory. Toric contact lenses, however, don't give much away in their name. Toric lenses are actually specially made to deal with astigmatism, which is a very common condition in Singapore. Astigmatism is the state where one's cornea is not evenly curved — this irregular shape causes light to refract incorrectly, which leads to blurry vision. In this blog, we will go through what exactly toric lenses are, and how they can help you with your astigmatism.
What Are Toric Lenses?
The word torus describes a shape that is somewhat like a donut. A toric lens is thus shaped as a slice off the side of a donut — oblong, like an American football — though not quite as dramatically pointed. The toric shape means that this lens has different curvatures on each of its axes, so to speak.
Toric lenses can be made of the same material as regular lenses; silicone hydrogel for soft lenses, or the Rigid Gas Permeable (RGP) lenses. These bring the same pros and cons as they do with spherical lenses — while the RGP lenses might be a little better at staying put, they are also more delicate and can feel drier. The soft lenses, on the other hand, require extra care in fitting to ensure that they snugly hug your eyes.
How Are Toric Lenses Different from Regular Lenses?
Unlike regular lenses, toric lenses have a different curvature on each axis. Fitting is especially crucial for toric contacts. In a case of the regular, spherical contact lenses, the optometrist will measure the curvature of your eyes to ensure a snug fit of the contact lenses.
With toric lenses, however, these measurements are different on different planes of the cornea, and so fitting toric lenses takes a little more expertise as compared to a fitting for a regular, spherical contact lens.
Since toric lenses have been designed to fit the specific curvature of your eye and are more curved on axes than the other, these contact lenses have a particular orientation, a "correct way" that they should sit on your eyes. Due to some very special design elements, you don't have to worry about putting in the contacts in this "correct" orientation — toric lenses might have thick-thin zones, which help your eyelids hold the thinner parts of the lenses in place, orientating the lens to its proper position.
Toric lenses might also make use of something called ballasting, where the bottom of the lenses are a little heavier such that each time you blink, it rotates itself into position.
How Do Toric Lenses Work?
Toric lenses are designed specially to combat astigmatism, a result of some changes or imperfections in the way that your cornea is shaped.
With astigmatism, light doesn't focus in your eye the same way it would with a perfectly spherical cornea. Because of the imperfections in the cornea, the light passing through does not all focus into one point, leading to smudged vision even with regular glasses or contact lenses. The different curvatures of the toric lens help mitigate this problem, as the toric lenses create different refractive or focusing powers that can help correct the astigmatism.
For severe cases of astigmatism, an RGP lens might be prescribed as these are able to retain their shape on the eye's irregular surface, correcting for the differences in focal points.
Buying Toric Contact Lenses in Singapore
Considering getting toric contact lenses? Be sure to check with an optometrist if your astigmatism requires you to wear toric lenses. If you do, prepare for the contact lens fitting to take longer
Visit us at our physical store in CentrePoint, where our experts can help you figure out if you need toric lenses with a free eye exam. You can also check out our high quality daily or monthly toric contact lenses at our online shop, with free shipping in Singapore when you buy above $50!