Imagine seeing the world like you are viewing it through an out-of-focus camera. That is what people with astigmatism see. This commonrefractive error— when the shape of your eye prevents light from focusing correctly on your retina — occurs in 33% of Americans, both young and old.
Below, we explain what causes astigmatism, how your eye doctor can test for it, and the three ways in which it can be treated.
Types of Astigmatism
If you think of a normal, healthy eye as a basketball, then an astigmatism is like having an eye the shape of a football. The front surface of the eye, known as the cornea, is not curved equally in all directions, which affects how light rays bend and the clarity of your vision.
In a normal eye, a smooth cornea(the outside surface of the eye)and lens (the clear part of the eye behind the colored iris) help focus light rays onto your retina (the thin layer of light-sensitive tissue that lines the back of the eye) to allow for clear vision. However, astigmatism causes light to focus on different parts of the eye. This results in a person seeing fuzzy or blurry images. It can also cause you to see halos, glare, or streaking around objects.
When there is a distortion of the cornea that affects vision, this is called a corneal astigmatism. It is the most common type of astigmatism. A lenticular astigmatism is a distortion of the lens.Trauma is often a cause of lenticular astigmatism.
Although astigmatism is common, eye doctors are unsure why cornea or lens shape varies by person. However, they do know it tends to be related to our genetics, so you are more likely to inherit it if it runs in your family. Astigmatism can also be acquired after an eye injury, disease, or surgery.
There are two types of astigmatism — regular or irregular — classified by their meridians, orsections of the eye formed byimaginary lines drawnoverthe eye that intersect at the pupil. There are also several other types of astigmatism you can develop with a refractive error that we’ll explore below.
Regular Astigmatism
A healthy eye has a spherical cornea or lens, meaning the curves are the same. However, an eye with astigmatism has a steep curve and a flat curve, also known as the two principal meridians. To visualize this, imagine the eye is a clock with a line running vertically from 12 o’clock to six o’clock (the 90-degree axis) and another line running horizontally from three o’clock to nine o’clock (the 180-degree axis).
Regular astigmatism is when the two principal meridians are 90 degrees apart, with one meridian being steeper than the other. This type of astigmatism is most common and can be corrected by glasses, contact lenses, or laser surgery.
Regular astigmatism can also be classified as “with-the-rule” or “against-the-rule” to describe its shape. In with-the-rule astigmatism, your cornea is shaped like a football lying on the ground with the steepest curves running vertically. This type of astigmatism is most common in younger people. With against-the-rule astigmatism, your cornea is shaped like a football on a tee with the steepest curves running horizontally. This type of astigmatism is more common in older adults.
Irregular Astigmatism
Whereas regular astigmatism occurs when the two principal medians are always at right angles, irregular astigmatism occurs when the two principal medians are not symmetric. In other words, the curvature is uneven, and this makes it harder to correct than regular astigmatism.
This type of astigmatism istypicallycaused by disease, such as keratoconus (gradual thinning of the cornea), corneal degeneration, corneal scarring, or ocular surfacedisease.
Astigmatism CombinedwithRefractive Errors
You can also have astigmatism combined with other refractive errors. Each of the five types is defined by the location of where the cornea focuses light on the retina, also known as the focal point.
In a normal eye, the meridians focus light at a single point on the retina. When you have astigmatism, the eye cannot focus light on a single point and instead creates two focal points.
For reference, myopic is another term for nearsightedness — when objects farther away are blurry — and hyperopic is another term of farsightedness — when objects close to you are blurry.
- Simple Myopic: This is a combination of astigmatism and nearsightedness in which one focal point comes before the retina, while the other is on the retina.
- Compound Myopic: This is a combination of astigmatism and nearsightedness in which both focal points come before the retina.
- Mixed: This is a combination of astigmatism and both nearsightedness and farsightedness in which one focal point is before the retina and the other focal point is behind the retina.
- Simple Hyperopic: This is a combination of astigmatism and farsightedness in which one focal point is on the retina while the other is behind the retina.
- Compound Hyperopic: This is a combination of astigmatism and farsightedness in which both focal points are behind the retina.
How to Test for Astigmatism
Acomprehensive eye examis the most accurate way to test for astigmatism. Your eye doctor can usea number ofdevices to test visual acuity and the curvature of your cornea.
A phoropter, an instrument with lenses and dials to test refractive errors, helps determine which type of lens correction you need. Your eye doctor willplacelenses with varying strengths in front of your eyes while you view aSnellen Chart.
Theymayalsomeasure how welllight focuses on your retinaby using an autorefractor. This device shines light into your eye andwhen the light bounces off the back of your eye it recordsany distortions in the return image to calculatethe proper correctionneeded.
Your eye doctor can also use akeratometerto measure the axis or the curvature of the cornea, although a corneal topographer is becoming increasingly popular to map and detail your cornea.
Astigmatism is measured in diopters, a unit of measurement of the refractive power of a lens. On a prescription, your eye doctor lists this measurement under “cylinder.” Typically, most people have an astigmatism between 0.5 and 0.75 diopters. A measurement of more than 1.5 diopters usually requires contacts or glasses to correct the astigmatism.
Cylinder is one of three measurements included in a prescription.The othertwo are “axis” and “sphere”.Measuring the axishelps identify an astigmatism by determining where on the cornea it is located. Your reading will be between 0 and 180 degrees, with the 90-degree axis running vertically across the eye and the 180-degree axis running horizontally across the eye.
Finally, the sphere reading on your prescription includes either a plus sign to indicate farsightedness or a negative sign to indicate nearsightedness. A higher number requires a stronger prescription.
How to Fix Astigmatism
There are three main ways to treat astigmatism: glasses, contacts, or refractive surgery.
Glasses
One of the most common ways to fix an astigmatism, glasses contain a cylindrical lens that compensates for the uneven curves in your cornea or lens. People with a severe astigmatism may be better suited for glasses instead of contacts.
Contacts
Like glasses, contactscanofferastigmatism correction, except they sit directly on your eye. There are several types of lenses available to correct astigmatism, including soft lenses, gas permeable contact lenses, and hybrid lenses.
- Soft contact lens:Toric lenses are a specific type of soft contacts used to treat astigmatism. The lensesare weightedto ensure theyremainaligned properly. They also have varying powers in different meridians (the imaginary perpendicular lines in your eye) to help correct your vision.
- Gas permeable contact lens:Also known as RGP or GP contact lenses,this type of lens is morerigid to help maintain its shape on the eye. Although rigid lenses can lead to sharper vision, the fit and feeling is not for everyone.
- Hybrid contact lenses:These lenses use rigid gas permeable lens material for the center of the contact surrounded by a soft material.
Refractive Surgery
Laser surgery reshapes the cornea to correct your refractive error. There are two surgical options: LASIK and photorefractive keratectomy (PRK). The maindifference between LASIK and PRKis how eye surgeons access the cornea.
- LASIK surgeryfeatures an ultrafast femtosecond laser that uses tiny pulses of light to create a flap that is folded back during the surgery so your ophthalmologist can access the cornea. An excimer laser then reshapes the cornea and smooths out any distortions to eliminate your refractive error.
- PRK surgeryinvolves removing the outer surface of the cornea, known as the epithelium, before reshaping the inner cornea with a laser. The epithelium regrows after surgery. PRK is an alternative to LASIK for people who have dry eyes or thin corneas.
Premium Lenses for Cataract Surgery
Although unrelated, people who have astigmatism and cataracts can receive corrective surgery to treat both conditions. In a typical cataract surgery, an eye surgeon removes the cloudy lens caused by cataracts and replaces it with a clear, artificial intraocular lens (IOL).However, people who also haveastigmatismcan receivepremium lens implantsto correctit.
Treating Astigmatism at DMEI
If you are experiencing blurry or distorted vision, schedule a comprehensive eye exam so one of our eye doctors can test you for astigmatism. DMEI offers several treatment options for astigmatism, including contact lenses, glasses, and laser surgery.
To schedule an eye appointment, call us at 405.271.6060 or 800.787.9012, or fill out our appointment request form using the button below.
If you are interested in LASIK, learn moreby clicking on the button below or calling 405.271.2500 to schedule your free screening.
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FAQs
What is astigmatism and how can it be corrected? ›
Astigmatism is a common type of refractive error. It means that some part of your eye (either the cornea or lens) is more curved than it should be. This altered eye shape makes your vision blurry. Most cases of astigmatism can be treated with corrective lenses like eyeglasses or contact lenses.
What causes astigmatism and how can it be corrected? ›Astigmatism happens when your cornea or lens has a different shape than normal. The shape makes light bend differently as it enters your eye, causing a refractive error. Doctors don't know what causes astigmatism, and there's no way to prevent it.
How can I fix my astigmatism permanently? ›Astigmatism surgery
Having surgery is the only way to permanently correct astigmatism. However, your type and degree of astigmatism, corneal thickness, age and other eye conditions are all factors in whether surgery is the best option — and if so, which type of surgery.
Astigmatism is an imperfection in the curvature of your eye's cornea or lens.
Can astigmatism be corrected naturally? ›By doing astigmatism eye exercises every day, you can improve poor vision due to astigmatism. You don't need to resort to eye surgery or surrender to a lifetime of eyeglasses. There are natural and easy ways to repair your vision yourself. Practice these eye exercises and a few more, and take a daily eye vitamin.
Can astigmatism be fully corrected? ›Yes, laser surgery can fully correct astigmatism and reduce or even eliminate the need for prescription lenses in most cases. However, the likelihood of a follow-up LASIK procedure increases with higher amounts of astigmatism. New LASIK options are available for individuals with higher levels of astigmatism and myopia.
What makes astigmatism worse? ›Astigmatism frequently worsens with age. Your cornea can become more irregular due to pressure from your eyelids as they lose muscle tone. Astigmatism generally stays stable until your turn 50. After then, your lens curvature progressively worsens each decade.
What can reverse astigmatism? ›Many people with astigmatism need glasses or contact lenses to see clearly, but if you want to cure your astigmatism, either LASIK (laser-assisted in situ keratomileusis) or PRK (photorefractive keratectomy) can correct your vision.
Can astigmatism be corrected with glasses? ›Can Glasses Help Astigmatism? Yes, glasses can correct astigmatism and dramatically clarify your eyesight. Glasses for astigmatism are fitted with corrective cylindrical lenses that help to properly refract light onto the retina of the eye.
What foods are good for astigmatism? ›Some of the best nutrients to add to your diet if you have astigmatism are zinc, magnesium, and calcium. You can get high servings of zinc by eating lima beans, oysters, and poultry. Magnesium is found in pumpkin seeds, soybeans, black beans, sunflower seeds, and halibut.
How do you stop astigmatism from progressing? ›
The natural aging process or other eye conditions can cause the shape of the eye to gradually change, which can intensify astigmatism. However, progressing astigmatism can usually be easily corrected with glasses or contact lenses, just like other progressing refractive errors.
What is the new treatment for astigmatism? ›Laser refractive surgery can reshape irregularities in the eye causing astigmatism and correct other refractive errors such as nearsightedness and farsightedness. This enables many to be less dependent on glasses and contacts.
Does astigmatism get worse with age? ›With age, the prevalence of astigmatism increases, and the axis shifts from a predominance of with-the-rule astigmatism to a predominance of against-the-rule astigmatism. This age-related change is caused by alterations in corneal curvature.
Can screen time cause astigmatism? ›Myth: Astigmatism worsens with screen time.
Fact: Whether it is your television, laptop, or tablet, being too close to the screen or staring at it for long periods of time will not cause astigmatism to get worse.
Glasses or contacts can correct almost all cases of astigmatism. But if you have only a slight astigmatism and no other vision problems, you may not need them. If you have a common level of astigmatism, you'll probably have corrective lenses, like glasses or contacts, or surgery.
What is the best solution for astigmatism? ›One of the most common ways to fix an astigmatism, glasses contain a cylindrical lens that compensates for the uneven curves in your cornea or lens. People with a severe astigmatism may be better suited for glasses instead of contacts.
Are there exercises to improve astigmatism? ›- Close your eyelids and place two fingers on each lid.
- With gentle pressure move your fingers from right to left, top to bottom in a circular motion.
- Move clockwise and counterclockwise 10-15 times repeating both the right to left and circular motions.
Lilium Tigrinum
This medicine is prominently indicated for cases of myopic astigmatism. Persons needing it have dim vision and can see clearly by turning the head sideways. It is accompanied with a headache in front of head.
Patients with 1.0 D or more of astigmatism are shown to benefit from correction during or after cataract surgery, as visual acuity can decline to 20/25 with 0.75 D and 20/40 with 1.5 D of astigmatism.
What happens if you don't fix astigmatism? ›If left untreated, astigmatism may cause eyestrain, headaches, and blurry vision. If you have astigmatism you may not see objects in the distance or near without some form of distortion.
Does rubbing your eyes worsen astigmatism? ›
Rubbing your eyes is one habit that could cause astigmatism. In fact, frequent rubbing could eventually change the shape of your corneas. Rubbing also increases your risk of keratoconus, a condition that makes the corneas thin and cone-shaped.
What do people with bad astigmatism see? ›What do people with astigmatism see? Individuals with astigmatism have blurred, fuzzy, or distorted vision at near and far distances alike.
What does it look like when you have astigmatism? ›For some people with astigmatism, objects can appear shadowy. Caused by the same focal point issue as blurry vision, incorrect eye curvature can make it look like every object has a translucent, ghost-like shadow. Whether a patient sees objects as blurry or shadowy, they certainly do not see with clear vision.
How can I get rid of astigmatism naturally? ›- Pull out a book.
- Place an object on the side. Focus on the side object after reading a paragraph from the book.
- It is advised to continue this until your eyes start to feel tired, 2-4 times a day.
Eyeglasses for astigmatism include a special cylindrical lens to compensate for how light passes through the cornea. Generally, a single-vision lens is prescribed, but in some patients over 40 years old, an eye doctor might recommend a bifocal or progressive.
Which lens is best for astigmatism? ›Toric contact lenses are best for astigmatism patients, as they are specially designed to correct the refractive error that is caused by having an irregularly shaped cornea.
Does everyone with glasses have astigmatism? ›Astigmatism does not always require the use of glasses. A person can have slight astigmatism and still see clearly. Similar to the rest of the body, the eyes change over time, so regular eye checks with your local optometrist are of importance.
Which vitamin deficiency causes astigmatism? ›Myopia may represent the end result of adverse emmetropization feedback generated by low vitamin D-related irregular corneal astigmatism.
Which is best fruit for eyes? ›| Foods Rich in Antioxidants for Eye Health | Antioxidants Related to Eye Health |
|---|---|
| Red berries, kiwi, red and green bell peppers, tomatoes, broccoli, spinach, and juices made from guava, grapefruit, and orange. | Vitamin C (ascorbic acid) |
Astigmatism may be present from birth, or it may develop after an eye injury, disease or surgery. Astigmatism isn't caused or made worse by reading in poor light, sitting too close to the television or squinting.
At what age does astigmatism stop progressing? ›
In most people, astigmatism stops progressing at age 25, but there are issues that can cause astigmatism to worsen over time, such as chronic infections, corneal trauma, and keratoconus.
At what age does astigmatism develop? ›Yes, you can develop astigmatism as you get older. A study showed that 1 in 4 people between 25 and 59 years old had astigmatism. But in people over the age of 60, that number doubles to 1 in 2 people. This happens because the shape of the cornea and lens can change as you age.
Why is astigmatism so expensive? ›It generally takes more expertise for an eye doctor to fit a patient for toric contacts than it does for regular lenses. For this reason, a toric lens fitting may cost more than a regular contact lens fitting. Since torics are more complex in design, the cost of replacing them will be higher than most regular contacts.
Can you develop astigmatism in your 60s? ›Most cases of astigmatism are hereditary and appear at birth. For some people, the condition can develop later in life.
Do people with astigmatism have better vision? ›But when you have astigmatism, this makes blurry vision worse. Your eye lets more peripheral light in, which can make lights look fuzzy and create a halo effect. Halos and glare from light can make it difficult to focus on tasks in the dark, such as driving at night.
Can you have 20 20 vision with astigmatism? ›You can have 20/20 vision and still have astigmatism. Unlike presbyopia that makes focusing on close objects difficult or impossible or myopia that makes focusing on distant objects difficult or impossible, astigmatism gives you sometimes clear vision and sometimes blurry vision at all distances.
Does using too much phone cause astigmatism? ›Overuse of Electronic Devices: The excessive use of smartphones, tablets, computers, and other electronic devices could lead to astigmatism, as well as dry eye. Improper Light Levels: Watching TV or using electronic screens in the dark can cause eye strain and eye fatigue and possibly be a cause for astigmatism.
Do smartphones cause astigmatism? ›Thus, the small but significant corneal astigmatism induced after smartphone use might degrade the overall optical quality of the eyes, and also distance and near vision.
Does computer affect astigmatism? ›Uncorrected vision problems like farsightedness and astigmatism, inadequate eye focusing or eye coordination abilities, and aging changes of the eyes, such as presbyopia, can all contribute to the development of visual symptoms when using a computer or digital screen device.
Do sunglasses help astigmatism? ›Non-glare lenses can help reduce the amount of light entering your eye, helping people with astigmatism see better at night.
Why can I suddenly see better without my glasses? ›
Why is that? Answer: Some call this "second sight" which has a simple physiological explanation. As the lens of the eye hardens as we age (the predecessor of frank cataracts) it changes the way light is "bent" as it enters the eye much the way different prescriptions in a pair of glasses do.
Do blue light glasses help with astigmatism? ›Blue light blocking lenses
In fact, excessive screen time can even cause digital eye strain, particularly for those with uncorrected astigmatism. Fortunately, blue light blocking lenses can alleviate this discomfort, and make working on your laptop or texting on your phone much more enjoyable.
Wearing corrective lenses treats astigmatism by counteracting uneven curvatures of your cornea or lens. Types of corrective lenses include: Eyeglasses. Eyeglasses are made with lenses that help compensate for the uneven shape of the eye.
Should I wear glasses all the time for astigmatism? ›Astigmatism does not always require the use of glasses. A person can have slight astigmatism and still see clearly. Similar to the rest of the body, the eyes change over time, so regular eye checks with your local optometrist are of importance.
How long do you have to wear glasses for astigmatism? ›It can go on for a week or 5 to 6 days if you have moderate or severe astigmatism. If the problems are less bothersome then give them enough time of 3 to 4 days but if it goes on to make you feel uncomfortable, visit your eye doctor and get your glasses checked.
What causes astigmatism to worsen? ›Astigmatism frequently worsens with age. Your cornea can become more irregular due to pressure from your eyelids as they lose muscle tone. Astigmatism generally stays stable until your turn 50. After then, your lens curvature progressively worsens each decade.
Can anything make astigmatism worse? ›Probably the most important thing to note about astigmatism is that it can worsen due to eye rubbing.
Does astigmatism get worse if you don't wear glasses? ›Not wearing glasses for astigmatism won't make your astigmatism worse, however. The severity of your astigmatism has nothing to do with whether or not you're using corrective lenses to treat it.
Can you have good eyesight and still have astigmatism? ›You can have 20/20 vision and still have astigmatism. Unlike presbyopia that makes focusing on close objects difficult or impossible or myopia that makes focusing on distant objects difficult or impossible, astigmatism gives you sometimes clear vision and sometimes blurry vision at all distances.
How do people with astigmatism see? ›How Does Astigmatism Impact Vision? Astigmatism leads to distorted or blurry vision at far and near distances. Light focuses on multiple points instead of just one. At night when looking at lights, they appear to bounce off their primary location.
How do people with astigmatism see at night? ›
Some of the effects of astigmatism at night include: Blurred or fuzzy vision. Light halos surrounding traffic lights. Starburst effects on lights.
Who is most affected by astigmatism? ›Astigmatism is often present at birth but it can also develop over time, and most often occurs with myopia (nearsightedness) or hyperopia (farsightedness). The rate of astigmatism significantly increases from 14.3% in the under 15-year-old age group to 67.2% in the age group of over 65-years old.