How Is Astigmatism Diagnosed? | The Eye Care Team

Explaining Astigmatism

You’ve probably heard the term astigmatism or know someone with this common vision problem, but you may not know the details of this condition or how it’s diagnosed. 

Astigmatism can result from an irregularly shaped cornea, or the lens inside the eye having a misshaped curve. These conditions change the way light reaches your retina, the light-sensitive surface located at the back of your eye. 

People with astigmatism often experience blurry or distorted vision. Vision problems can increase or decrease due to changes in the curvature of the lens inside your eye. 

Optometrists cannot prevent astigmatism because it is an abnormality of the eye, but various treatments are available to help patients achieve clear vision. 

There are 2 types of astigmatism: 

• Corneal astigmatism: This condition occurs when the cornea is irregularly curved.  
• Lenticular astigmatism: This condition occurs when the lens is irregularly curved. 

What Causes Astigmatism? 

Experts cannot agree on why cornea and lens shapes vary from person to person, but studies indicate that this condition could be genetic. Astigmatism can present itself at birth, develop later in life, or occur due to an eye injury. 

Nearsightedness (myopia) and farsightedness (hyperopia) often go hand-in-hand with astigmatism. These conditions are referred to as refractive errors because they affect how the eye bends light. 

You are at a higher risk of developing astigmatism if you: 

• Have a family history of astigmatism. 
• Have a family history of eye diseases, like keratoconus.
• Have scarring on your cornea. 
• Have corneal thinning. 
• Have pronounced nearsightedness (myopia).
• Have pronounced farsightedness (hyperopia).
• Have had eye procedures in the past, like cataract surgery.  

Symptoms of Astigmatism

Some patients have this condition, but don’t experience any symptoms. Each person is different, and symptoms can vary in severity. 

People with astigmatism may experience the following symptoms: 

• Blurry vision at any distance 
• Distorted vision at any distance 
• Issues with seeing at night 
• Eye discomfort 
• Eyestrain 
• Squinting 
• Irritated eyes 
• Frequent headaches

It’s important to note that even with these symptoms, you may not have astigmatism. Always speak to your optometrist for a diagnosis and options for treatment. 

Diagnosing Astigmatism 

Great news! Your optometrist can diagnose astigmatism at your routine comprehensive eye exam. There are several tests and devices available to help your doctor achieve precise results: 

Visual Acuity Assessment 

Your optometrist will ask you to read a series of letters on a distance chart to assess your clarity of vision at certain distances.  

Refraction Test

In a refraction test, the doctor places various lenses in front of your eye, and uses light to measure how it bends through your cornea. Following this, a phoropter may be used to evaluate the focusing power of your eyes, helping the optometrist find a lens that allows the clearest possible vision. 

Keratometry 

Keratometry helps your optometrist evaluate the curvature of your cornea. This test is conducted by focusing a circle of light on your eyes’ curve and measuring the reflection. 

Corneal Topography

Corneal topography is becoming a more popular method of diagnosing astigmatism. This computer-assisted diagnostic tool creates a contoured map of the cornea and provides your optometrist with the precise details of its shape. 

Treatments for Astigmatism 

Not every patient with astigmatism experiences vision problems, but treatments are available if your eyesight is affected. 

Corrective Eyeglasses & Contact Lenses 

Your optometrist can correct vision problems associated with astigmatism by providing eyeglasses and contact lenses with a special cylindrical lens. This lens helps compensate by giving additional power to a specific area in the visual field. 

Many patients are interested in frame-less vision correction, and initially, optometrists could use only rigid contact lenses to help with astigmatism. However, there are now soft lenses available called toric contact lenses. 

Everyone’s eyesight is different, and we recommend contacting our experts at The Eye Care Team to discuss the best lens options for your vision. 

Orthokeratology (Ortho-K) 

Ortho-K lenses are generally worn overnight. These lenses are designed to mold the cornea into an ideal shape. This corneal reshaping helps light focus correctly on the retina, providing clear vision during the day without the use of contact lenses or glasses.  

The visual corrections from these lenses are only temporary, but patients can maintain clear vision with regular use. 

Surgery 

For patients with more severe cases of astigmatism, your optometrist may recommend procedures like LASIK or PRK.  

Laser-assisted in situ keratomileusis (LASIK) is a popular surgery for refractive errors, where an ophthalmologist reshapes corneal tissue using a pre-programmed laser to the desired prescription. 

Photorefractive keratectomy (PRK) is another type of laser eye surgery. The main difference between PRK and LASIK is how your doctor gains access to the corneal tissue.

Life With Astigmatism 

You’ve received your diagnosis from the optometrist, so now what? 

Astigmatism is a common vision problem, and studies have shown that approximately 1 in 3 Americans have this condition. Everyone’s eyesight is unique, and some patients will experience more pronounced symptoms; others will not notice a change at all. 

The most vital step is to select a treatment that works best for your vision and your lifestyle. 

If you have questions about astigmatism or would like to book a comprehensive eye exam, contact one of our friendly experts at The Eye Care Team. We can help guide you through your initial diagnosis and help get you on the path to clearer vision. 

What Is Astigmatism? Symptoms, Causes, Diagnosis, Treatment

Astigmatism is an imperfection in the curvature of your eye’s cornea or lens.

In this article:

• Video: What Is Astigmatism?
• What Is the Main Cause of Astigmatism?
• How Does Astigmatism Affect Vision?
• How Can You Tell if You Have Astigmatism?
• Astigmatism Diagnosis
• How Is Astigmatism Corrected?
• Video: LASIK for Astigmatism

To understand astigmatism, it is helpful to think of the normal eye as evenly rounded, like a basketball. With astigmatism, the eye is egg- or oval-shaped like an American football. There are two basic types of astigmatism:

• horizontal astigmatism (when the eye is wider than it is tall), and
• vertical astigmatism (when the eye is taller than it is wide)

With either type of astigmatism, near and far vision is blurry because of the eye’s irregular shape.

Video: What is astigmatism?

What Is the Main Cause of Astigmatism?

Astigmatism is caused by a cornea or lens that has a different shape than normal. Astigmatism is very common. Doctors don’t know why the shape of the cornea or lens varies from person to person. But they do know the risk of getting astigmatism is inherited (passed down from parents).

People can also get astigmatism from:

• eye disease
• eye injury
• or after surgery

It is a myth that reading in low light or sitting very close to the television causes astigmatism or makes it worse.

How Does Astigmatism Affect Vision?

Normally, the cornea and lens at the front of the eye have an evenly round shape. This helps focus light rays sharply onto the retina so you can see clearly.

With astigmatism, light rays do not refract (or bend) properly as they enter the front of the eye. Vision is blurry at near and far because light rays either fall short of the retina or behind it.

People may have astigmatism along with other refractive errors, such as: 

• nearsightedness (myopia) or
• farsightedness (hyperopia).

In a normal eye, the cornea and lens focus light rays on the retina.

In astigmatism, images focus in front of and beyond the retina. Close and distant objects both appear blurry.

How Can You Tell If You Have Astigmatism?

Astigmatism symptoms may include:

• blurry vision or areas of distorted vision
• eyestrain
• headaches
• squinting to try to see clearly, or
• eye discomfort

These symptoms do not always mean you have astigmatism. See your ophthalmologist for a comprehensive eye exam to find out what is causing your symptoms.

Children may not realize they have blurry vision. And they are unlikely to complain about blurred or distorted vision.

But without treatment, astigmatism can:

• impact a child’s performance in school and sports
• lead to amblyopia (lazy eye) and vision loss

This is why early childhood eye screenings—by a pediatrician, family doctor or other eye care professional—are so important. If astigmatism or another eye problem is found, see an ophthalmologist to get the right treatment.

Astigmatism Diagnosis

Ophthalmologists can diagnose astigmatism during a comprehensive eye exam. Testing may include:

• Eye chart. You will be asked to read letters on an eye chart. This tests for visual acuity or sharpness of your vision at certain distances.
• Phoropter. This is where you look through a large binocular-like device and tell your doctor which letter you can see better. Based on your answers, your doctor writes a prescription to provide you with the clearest vision possible.
• Autorefractor. This device also helps measure your astigmatism or other refractive error. It works by shining a light into the eye and measuring how it changes as it bounces off the back of the eye.
• A keratometer measures the curve of your cornea. Your eye doctor may also do a corneal topography scan, which helps find imperfections and distortions on the corneal surface.

A phoropter helps your eye doctor find out your prescription for glasses or contact lenses.

How Is Astigmatism Corrected?

• Eyeglasses or contact lenses. They work by refocusing light on the retina in the back of your eye so that you can see more clearly. There are two main types of contacts for astigmatism: toric soft lenses and RGP (rigid gas permeable). For more severe astigmatism, RPG lenses may work best.
• Refractive surgery. With LASIK and other procedures, a laser reshapes the cornea to adjust how light travels through it.

There is no best way to correct your astigmatism—the most appropriate correction is one that best suits your vision needs and lifestyle. You and your ophthalmologist can discuss your options in more detail after your exam.

Video: LASIK for astigmatism

causes, symptoms, diagnosis and treatment of astigmatism

What is astigmatism?

Astigmatism is a condition of the visual apparatus in which there is no single focal point on the retina to create a clear image. Some parts of the image can focus on the retina, others behind it, as in farsightedness, and others in front of it, similarly to myopia. This results in blurry and distorted images. Depending on what caused such visual impairment, there are two types of astigmatism:

• corneal,
• crystal.

In the first case, the pathology occurs due to the non-spherical surface of the cornea, in the second – the lens. Corneal astigmatism affects vision more because the cornea has a greater refractive power.

What are the degrees of astigmatism?

Depending on how severe visual anomalies in astigmatism are, ophthalmologists distinguish three degrees of the disease.

Weak. Vision with such astigmatism is impaired by no more than 3.0 diopters. The patient may have complaints of impaired visual acuity of varying intensity.

Medium. Visual impairment is in the range of 3.0–6.0 diopters. This degree of astigmatism is a serious visual impairment and leads not only to its deterioration, but also to a constant feeling of eye fatigue, headaches.

High. This degree of astigmatism implies a deviation of the patient’s vision from the norm by more than 6.0 diopters. This pathology can lead to a violation of binocular and stereoscopic vision, the development of strabismus and other pathologies.

How to recognize astigmatism?

In addition to the main symptom of astigmatism – decreased vision – there are others. You should contact an ophthalmologist for diagnostics if you have the following symptoms:

• discomfort in the eyes, irritation;
• headaches, especially in the superciliary region;
• fatigue when working at a computer and other loads;
• difficulty focusing on thin lines, printed words;
• blurry or distorted image;
• difficulty in seeing objects near and far.

What are the characteristics of childhood astigmatism?

Most people are born with slight astigmatism, and this is not a severe pathology and may not affect the quality of vision. The problem with astigmatism in children is that it is difficult to diagnose. After all, the child does not understand that he sees poorly, and therefore does not complain about vision problems. In most cases, he simply refuses to write or read, which adults often mistake for whims, not noticing the problem. In order to identify the signs of astigmatism in time, it is worth carefully observing the behavior of the child: he can squint his eyes, tilt his head to see better, complain of headaches and difficulty reading books. If at least one of these symptoms appears, you should consult an ophthalmologist.

How is astigmatism diagnosed?

To diagnose astigmatism and choose the right method of correction and treatment, the specialist applies:

• study of the structure of the eye;
• study of refraction;
• shadow sample;
• visometry;
• biomicroscopy to determine the cause of astigmatism;
• examination of the vitreous body;
• Ultrasound of the eye.

How is astigmatism treated and corrected?

Today there are three types of astigmatism correction. Choosing which one to prescribe, ophthalmologists are guided by the degree of the disease, the age of the patient, and concomitant pathologies of the organs of vision.

Spectacle correction. The most common correction option, although it is not well tolerated by some patients. With astigmatism, the patient is prescribed special glasses with cylindrical lenses. It is very important to choose them correctly, because otherwise the patient will feel discomfort in the eyes, pain, headache or dizziness. There are cases when, after an incorrect diagnosis, you have to change glasses several times.

Contact correction. An alternative to glasses is contact lenses. Previously, only rigid lenses were used to correct astigmatism, which caused a lot of inconvenience when worn, but today soft toric lenses are also used. For their selection, you must contact the optician to an ophthalmologist.

It should be remembered that after the appointment of contact lenses or glasses, it is worth having a regular examination with an ophthalmologist.

Laser correction. Laser correction of astigmatism is possible only in patients over 18 years of age. It is performed under local anesthesia and does not require stitches. Like any surgical intervention, this operation has certain contraindications and side effects, therefore, before this intervention, a complete ophthalmological examination of the patient and an assessment of the ratio of risk factors and the expected benefits are performed.

Eye test for astigmatism online and in optic city salons in Moscow

Astigmatism is a feature of the structure of the eye, in which the refractive power of various eye media does not allow the rays to focus at one point. That’s why with astigmatism the image is always blurry. Most often, the reason lies in the irregular shape of the cornea, less often in the abnormal shape of the lens: the cornea or lens has an elliptical rather than a spherical surface.

Ophthalmologists say that the human eye as a whole is not perfect. And the astigmatic form, to one degree or another, can be present in any person who sees quite clearly at the same time. We have to talk about correction when astigmatism has such a magnitude that it interferes with seeing objects well and the use of correction tools is required – special spectacle and contact lenses.

Specialist diagnostics

Where does it all start?

Most often, astigmatism is a congenital visual impairment. The diagnosis of “astigmatism” ophthalmologists can put the patient in early childhood. The earlier the correction is carried out, glasses or contact lenses are prescribed, the more likely the full development of visual acuity. At preschool age, a child does not understand that there are some vision problems, because his brain has always received information in a slightly modified form and does not “know” that the image of his other peers looks much clearer. If parents do not pay attention to some features of the child, for example, tilting the head, squinting one eye, then astigmatism may not be detected in time.

With the beginning of schooling, the child begins to complain of rapid visual fatigue, headaches during lessons. The teacher can draw the attention of parents to the slow speed of assimilation of information, inattention, poor handwriting.

At an older age, other symptoms of this disease may also appear:

• in addition to a blurry picture, some colors may also be distorted;
• often with visual stress there are unpleasant sensations of burning, “sand” in the eyes;
• with prolonged eye strain and the absence of astigmatism correction, the image begins to double;
• one of the signs of astigmatism is tension headache.

In all these cases, it is necessary to have your vision checked by a specialist as soon as possible.

Make an appointment with a doctor

Astigmatism test at home

If all of the above symptoms are familiar to you, but you are still in doubt, you can test your eyesight yourself.

Qualitative tests are used for diagnosis.

Search the internet for a Siemens star test. It is a circle consisting of rays of equal length diverging from the center. Move 5 steps away from the screen and, covering one eye with a sheet of paper, look at the picture. Then check with the other eye. With the existing astigmatism, the outer border of this circle takes the form of an ellipse.

Another test, when parallel horizontal and vertical lines are drawn on the picture, also allows you to independently determine your violations. Alternately look at the picture with your right and left eyes. If the lines are seen unevenly, some of them have different thicknesses or become gray, less clear – this confirms the presence of astigmatism.

Checking for astigmatism in the ophthalmologist’s office

Only an ophthalmologist can make a final diagnosis and determine the meaning of astigmatism. Therefore, do not neglect the professional diagnosis of vision, especially since the doctor can fully check the vision and prescribe the correct correction for this disease. As with other visual impairments, the ophthalmologist diagnoses visual acuity, evaluates the condition of the eyes, objective and subjective vision of patients of surrounding objects, text. OPTIC CITY salons also carry out computer refractometry. Such a study most accurately determines the state of optical media and fixes the existing deviations. Keep in mind that a child with a high degree of astigmatism requires mandatory correction, otherwise it can lead to a significant deterioration in vision in the future.

Salon map in Moscow

Astigmatism correction tools

Modern optometry offers patients with astigmatism two types of correction – spectacle or contact. However, the choice depends on many factors, including the personal feelings of the person.

Astigmatism combined with farsightedness or nearsightedness. If glasses that the patient has been using for a long time did not have a special cylindrical component, then new spherical lenses may take some getting used to.

Choose a frame

A big step in the field of contact correction is the lenses, which are called astigmatic or toric. Almost every manufacturer has a line of soft toric lenses that have all the advantages of conventional spherical lenses:

• they are made from the latest materials with high oxygen permeability
• toric lens material often has built-in wetting agents that provide exceptional comfort
• stabilization technology allows you to keep the lens on the eye in the correct position, which is important for
  high definition vision.

OPTIC CITY specialists have extensive experience in astigmatism correction, and also have a full arsenal of
modern means for diagnosing this disorder, including in children.