Understanding Astigmatism: A Comprehensive Overview

Welcome to our comprehensive guide on astigmatism, a prevalent eye condition that impacts many people. In this article, we’ll take a closer look at what astigmatism is, how it affects your vision, and its connection to other refractive errors. We’ll also explore the potential causes behind astigmatism and emphasize the importance of regular eye exams for early detection. Furthermore, we’ll delve into the various treatment options available, from glasses and contact lenses to surgical procedures. Stick around to gain a deeper insight into this common vision problem.

What is Astigmatism?

Astigmatism, although sounding like a complex eye condition, is in fact, a very common focusing error or also known as a refractive error (in optical terms). It is a vision condition that results in blurry vision and occurs because the natural shape of your eye prevents the light from being focused correctly on the retina, the light-sensitive tissue which lies inside and to the back of the eye. Refractive errors can be caused by a long or short eye, the curve at the front of the eye and age changes in the part of the eye called the lens. It is estimated to affect 1 in every 3 people. The good news is that it is very easy to correct and its presence is always assessed in an eye exam.

Astigmatism most commonly occurs with myopia or hyperopia, two other types of refractive error. Unlike these, astigmatism does not have another term that is commonly used to describe it. Myopia (short-sightedness) will cause distant objects to be blurry and hyperopia (long-sightedness) will cause near objects to be blurry. Myopia starts during childhood and progresses throughout puberty whereas hyperopia when present, changes very little during this period. Astigmatism is so common with other refractive errors, that up to 90% of people who need vision correction, in one way or the other, have astigmatism included in their prescription.

Even though you may have some astigmatism, it may or may not affect your vision. Many have astigmatism but have no concerns with their vision. The more astigmatism you have, the more it can affect vision and become symptomatic. The symptoms of astigmatism include blurry vision, eye strain, headaches, eye discomfort, and halo or glare around car lights or streetlights. Even small amounts of astigmatism can impact your vision if you use a computer throughout the day.

What is the main cause of Astigmatism?

The exact cause of astigmatism is unknown, but this usually do not affect the ability for it to be corrected fully. It is most likely caused by a combination of your genes, the visual tasks you perform over many years, and/or interactions between the different parts of the eye like the cornea, eyelids, and eye muscles. Either way, in all but a few, symptoms from astigmatism can be corrected.

Astigmatism commonly occurs because of unequal curves in the cornea at the front surface of the eye (imagine a round football vs a rugby ball).

The amount of astigmatism is typically the same between both eyes, but an unequal amount may indicate a problem with the cornea.

Usually, astigmatism in young children tends to be hereditary, often running in families and appearing more frequently in certain ethnic populations. Research shows similarities in the forms of astigmatism between parents and their children. A newborn baby typically has a high amount of astigmatism which is normal and decreases as they age, in the first few years. If a child has a high amount of astigmatism that is not corrected with spectacles, their vision may not develop normally. This astigmatism can lead to a condition called amblyopia (often times called a “lazy eye). Young children wearing spectacles may have large amounts of astigmatism and will wear a patch over one eye to encourage the other eye to develop normally.

At times, abnormal astigmatism can develop after an injury or surgery and your eye-care professional will be able to let you know why it has developed. Pterygia, and keratoconus are common eye conditions that may also change your astigmatism. Keratoconus is a fairly common corneal condition that is estimated to affect approximately 1 in 2,000 people around the world and results in poor vision.

How can you tell if you have Astigmatism?

While you may suspect you have astigmatism due to your symptoms, it is impossible to know if you have it without having an eye examination. If you have any of the above symptoms, you should see an eye-care professional.

When to see an Eye-care Professional?

Even if you have 20/20 vision, having your eyes examined is important. An eye examination is not just about your vision but about the health of the eye. It is possible to have perfect vision and have an eye condition. You may even benefit from a small prescription for astigmatism or hyperopia for using your phone or your computer.

Here are the recommendations for how regularly you should visit an eye-care professional depending on your age:

• Children from birth to 2 years of age should have their eyes examined at 6 to 12 months of age (to detect any high levels of astigmatism that could lead to amblyopia).

• Children aged 3 to 5 should have an eye exam at least once a year or more frequently if needed.

• Children aged 6 to 17 years of age should be seen before they start first grade and every year after.

• Adults aged 18 to 64 should be seen by an eye-care professional at least every two years, but if they are of risk, an annual visit is recommended.

• Adults aged 65 and above should be seen annually or as recommended.

Of course, while this is based on age, an eye examination is recommended if any changes to vision or other symptoms are experienced. Your Eye-care Professional will recommend the frequency of eye examinations thereafter.

How is Astigmatism detected in an Eye Exam?

Now that you know how frequently you should go, let’s dive in more into how the exam actually goes.
At first your eye-care professional will likely use the Snellen Acuity Chart to check your vision. This value provides a measure of your vision. 20/20 vision is used to describe normal vision (clarity or sharpness). If you are told you have 20/20 vision, it means you can see clearly at 20 feet what should normally be seen at this distance.

While this test gives important information on your best vision, a refraction is needed to assess if you have astigmatism. A refraction is the test where you are asked which option you prefer, 1 or 2, and the Eye-care Professional uses your selection to pinpoint your prescription. They use a series of choices to fine tune your vision and arrive at a prescription for your glasses. If you have astigmatism, they will find and correct it in your glasses.

How do you correct Astigmatism?

Astigmatism can be corrected through various methods ranging from eyeglasses, toric soft or rigid contact lenses, to refractive surgeries like LASIK. The best method depends on individual needs and can be discussed with an Eye-care Professional.

Spectacle Lenses

Spectacles are by far the most common way to correct astigmatism. As astigmatism is commonly associated with myopia and hyperopia, the spectacles lenses prescribed need to correct both refractive errors (eg. astigmatism and myopia) making them more complex than standard lenses. However, they can still be made from lightweight materials and designed to achieve clarity, comfort and better looks. Protecting the lenses with scratch resistant and anti-reflecting coatings makes them more durable and easier to clean especially when it comes those annoying smudges. Your astigmatism prescription can also be corrected for sunglasses without limiting frame choices.

SeeMax Infinite, one of the most advanced Nikon Sepctacle Lenses, exceptional vision solution if you are diagnosed with astigmatism. The lens provides visual comfort, sharp vision, superior aesthetics, and can be personalised for your visual needs. An exclusive feature of this lens is the ability to minimise optical aberrations present in standard corrective lenses SeeMax lens is optimised based on the shape of the frame that you select resulting in even sharper and clearer vision.

Soft & Rigid (Orthokeratology) Contacts Lenses

Soft contact lenses for astigmatism offer improved comfort and moisture compared to older versions. Specific rigid contact lenses (orthokeratology rigid lenses) worn overnight to reshape the cornea temporarily, can also be effective for astigmatism. However, these lenses need to be worn every night otherwise the cornea will return to its natural shape and the astigmatism, and any other refractive error will return.

Refractive Surgery

Refractive surgery is another option for correcting astigmatism as it is most commonly found with other refractive errors. Some eye conditions that can be the cause of astigmatism may not be suitable for this type of surgery.

Conclusion:

While the exact cause of astigmatism is unknown, it is thought to be a combination of your genes, your environment, and how the eye ages normally. While not everyone with astigmatism requires spectacles, if you are struggling with your vision or eye fatigue, an eye exam will confirm your diagnosis. The blurry vision, halos, eye fatigue, and headaches caused by astigmatism can be corrected with spectacles, contact lenses and/or refractive surgery. Your vision is precious — and Nikon Lenswear strives to develop the best spectacles lenses to correct your astigmatism.