Astigmatism is a condition which causes blurry or distorted vision. It occurs because the cornea or lens in the eye has an irregular curvature, meaning the eye cannot focus light properly on the retina.
It can be part of your prescription, along with refractive errors such as myopia (short-sightedness) and hyperopia (far-sightedness).1
Astigmatism is characterised by varying amounts of short-sightedness and far-sightedness in different meridians of the eye (connecting circles on the front of the eye).2 This creates two points of focus within the eye that need correcting, often known as ‘rugby ball shape’, and can be easily corrected with glasses or contact lenses for astigmatism.
What are toric contact lenses?
If you have been diagnosed with astigmatism, your optician may recommend that you need toric contact lenses. These are designed to correct astigmatism, are very common and are available in different wear schedules, such as daily, weekly, monthly and yearly replacement hard lenses.2
How do toric lenses differ from other contact lenses?
Regular spherical contacts have one power across the entire lens and are effective even if they rotate with blinking.
Toric contact lenses have different powers in the horizontal and vertical meridians. They must remain rotationally stable in the eye for effective vision correction. So, toric contact lenses have special design features to ensure that the lens sits on the eye correctly and has minimal movement, to ensure sharp vision. They also have specific features, such as a weighted bottom, to prevent them from rotating.2
Expert fitting is required for toric contact lenses. A trial of more than one design and brand may be needed to find the lenses with the best comfort and visual acuity.2
Can you wear gas-permeable contact lenses for astigmatism?
Yes, rigid gas-permeable (RGP or GP) contact lenses can be used to correct astigmatism. Unlike soft contacts, RGP contact lenses for astigmatism do not always require a special toric design. This is because the rigid material retains its shape when applied to the eye (unlike soft lenses that conform to the irregular shape of the cornea).
RGP contact lenses compensate for the misshapen cornea and provide a uniform surface for light to pass through. As a result, they can sometimes correct astigmatism without the need for a special toric design.2
Many people with astigmatism find that RGP lenses provide noticeably sharper vision than soft contact lenses for astigmatism. However, because of the rigid material and thicker lens, it can take several weeks of adjustment to become accustomed to the RGP lens on the eye.
RGP contact lenses for astigmatism are custom-made and, therefore, cost more than soft toric contact lenses. Replacement lenses are also more expensive. Fitting requires more expertise and time than soft contact lenses for astigmatism.2
Can aspheric contact lenses help astigmatism?
In an aspheric contact the power changes gradually from the centre to the edge of the lens. This is believed to minimise aberrations and improve depth perception and contrast sensitivity.3 Optometrists will sometimes prescribe aspheric contact lenses to people with low levels of astigmatism. However, the effectiveness of an aspheric contact lens depends on several factors, such as:
- Pupil size
- Ocular shape
- Refractive error
Each of these varies from person to person. Therefore, an average design may not improve vision for the majority of wearers. Aspheric contact lenses may help astigmatism in some individuals with large pupils and high refractive errors, particularly hyperopia (far-sightedness).4
Daily toric contact lenses for astigmatism
Astigmatism is very common and daily disposable contact lenses are popular because of their convenience. Specsavers sells daily contact lenses for astigmatism. These are single-use toric contact lenses that are discarded after one wear. They give people with astigmatism all the advantages of daily disposables, including comfort and ease of use.
Daily contact lenses for astigmatism are suitable for people who use contacts only occasionally. They are also convenient for people with a busy lifestyle, those who travel frequently, and those who wear contact lenses for sports and other activities. Because daily disposables require no cleaning or storage, they are recommended for wearers young or old who are, perhaps, more likely to ignore proper cleaning and storage practices and may forget to change the contacts on schedule.5
You can learn more about daily contact lenses here.
Monthly toric contact lenses for astigmatism
Monthly toric contact lenses for astigmatism are soft contact lenses that can be worn daily and re-used but must be changed for a fresh pair every 30 days after opening. They’re suitable for people who wear contacts every day and are looking for a more durable and affordable option than daily disposables.
Monthly contact lenses for astigmatism require more care than dailies and must be disinfected and stored overnight.6
You can learn more about monthly contact lenses here.
Multifocal toric contact lenses for astigmatism
Astigmatism is a very common condition that can occur at any age. Presbyopia is also very common and usually occurs at age 40 to 45 when objects up close (such as a menu card or book) appear blurred. Varifocal toric contact lenses address both problems – astigmatism and presbyopia.2 Trusted brands have developed varifocal toric lenses with advanced optical technologies that permit same-day fitting.7
Learn more about multifocal contact lenses here.
Short- and far-sighted astigmatism differences
Astigmatism occurs due to an imperfect curvature of the eye that results in blurring of vision at all distances, near and far. It is often present from birth and is an easily treatable condition. If it is mild, no corrective action may be necessary. If it is pronounced, corrective contact lenses can help.
Astigmatism can occur in combination with refraction errors (short-sightedness and farsightedness). Standard soft contact lenses correct the refraction errors but do not correct astigmatism. Special toric contact lenses for astigmatism are available in a wide range of powers to correct the short-sightedness or far-sightedness with additional cylindrical power and axis for astigmatism correction.
Become a member of the Specsavers easycare package for contact lens users and benefit from free eye checks and contact lens follow-ups, free deliveries every quarter, a free pair of spectacles, free replacement lenses, and access to a dedicated contact centre.