Astigmatism vs. Myopia: What’s the Difference?

Astigmatism vs. Myopia s

Astigmatism Vs. Myopia

Myopia (commonly known as shortsightedness) and astigmatism are examples of refractive errors that cause blurry vision, and while similar, they are two separate conditions. The main difference between the two conditions is that they are two distinct refractive errors, individuals who suffer from myopia will experience blurred vision at longer ranges, whereas individuals who suffer from astigmatism will experience blurred vision at all ranges. The final refractive error term is astigmatism, which occurs when the front window of your eye — your cornea — is oval, or football-shaped, instead of round

What is Astigmatism?

Astigmatism is a common, usually treatable defect of the curvature of the eyes, which causes fuzzy distance and near-vision. It is a problem that occurs when the lenses in front of your eyes concentrate light more heavily in one direction than another. The lens distortion – located right in front of your eyes – causes lenticular astigmatism.

Related Blog: Astigmatism: Causes, Types, Symptoms & Treatment

What is Myopia?

Myopia is a common eye condition characterized by nearsightedness, which is a refractive error that causes blurred or distorted images when looking at faraway objects. The condition can be mild, moderate, or severe and can affect both children and adults. It is also called short-sightedness or nearsightedness and affects approximately 16 percent of the world’s population. It results in blurriness and distortion of faraway objects because the eye lens is too long or has been stretched. The condition can be mild, moderate, or severe, and it can affect both children and adults. There are several different types of myopia including juvenile myopia (occurring during childhood), adult-onset myopia (occurring later in life), and high myopia (occurring when people are very nearsighted). Myopia is also called short-sightedness or nearsightedness.

Astigmatism Vs. Myopia: Differences

Myopia and astigmatism are different in some ways, but they are similar in others. The primary difference between the conditions is that they are two distinct refractive errors, with myopia preventing proper focus on objects over a long distance, while astigmatism causes blurred vision at any distance. An astigmatic eye, in contrast, has two different refracting powers of light, and therefore there are two focus points inside the eye affecting visual acuity.

  • Astigmatism occurs when your eye’s lens or front surface is irregular or cylindrical. Myopia occurs when the whole eyeball is too long, or the cornea is too steeply curved.
  • Astigmatism may also cause blurry near vision. Degenerative myopia can cause other ocular conditions to develop, such as retinal problems which impact central vision.
  • Myopia usually develops between the ages of 8 to 14 years and can stabilize around 15 to 21 years old. Astigmatism on the other hand can happen at any age.
  • Myopia results in light entering the eye is focused in front of the retina. In astigmatism, light is focused on multiple points on the retina.
  • Astigmatism Vs. Myopia: Types

    Types of Astigmatism

    Corneal Astigmatism –
    Corneal astigmatism is when the cornea has an irregular shape. This is the more frequent type

    Regular and irregular astigmatism

    • Regular astigmatism: The principal meridians are perpendicular to each other and form a 90º angle. Most astigmatisms are regular and are of the cornea.
    • Irregular astigmatism: The principal meridians are not perpendicular. It may be the consequence of an injury or surgery that has caused the scarring of the cornea. In addition, it may be caused by a keratoconus, an eye problem which causes the thinning and deformity of the cornea.

    Simple astigmatism

    • Simple myopic astigmatism: One of the two principal meridians of the eye focuses light rays in front of the retina. The other focuses correctly onto the retina.
    • Simple hypermetropic astigmatism: One of the two principal meridians focuses rays of light behind the retina. The other focuses correctly onto the retina.

    Compound astigmatism

    • Compound myopic astigmatism: The two main meridians of the eye focus light rays in front of the retina.
    • Compound hypermetropic astigmatism: The two principle meridians focus light rays behind the retina.
    • Mixed astigmatism: One principle meridian focuses the light in front of the retina and the other behind.

    2. Types of Myopia

    There are two types of myopia.

    • The first one is simple myopia (which is not considered a visual disease) which is less than 6 diopters.
    • The second one is high myopia, when the patient exceeds 6 diopters, it is then an eye disease.

    Astigmatism vs. Myopia: Symptoms

    Some people are born with this defect. In fact, the majority have a certain degree of astigmatism that may be combined with other refraction defects, such as myopia or hypermetropia.

    Symptoms of Astigmatism

    Astigmatism is a vision disorder that causes your eyes to focus on different parts of the retina. The most common symptoms are:
    When you look at something for the first time, you may notice that your vision is blurry. This is because the retina, which is located in the back of your eye, is not receiving enough light. If this happens often, it could be a sign of astigmatism. Another symptom of astigmatism is that your vision may not be as sharp as it should be. This can be caused by the way your eye focuses on different parts of the retina. Astigmatism can also lead to other problems, including: If you have astigmatism, you should get regular eye exams to make sure that it doesn’t get worse. You may also need glasses to correct it when it gets worse.

    Symptoms of Myopia

    The most common form of myopia include –

    Presbyopia – caused by a loss of vision as a person ages. As a person ages, the lens in their eye gets thinner and thinner, causing it to focus more on distant objects. As a result, they are unable to focus on close objects as well as they used to.

    Hyperopia – caused by an increased amount of light being reflected off the retina. This increase in light can be caused by a change in your environment, or an increased amount of light entering your eye. As a result, your eyes are not able to adjust to the increased amount of light and become hyperopic (too far away from the retina). Hyperopia can be prevented with glasses or contact lenses.

    Astigmatism vs. Myopia: Causes

    1. Causes of Astigmatism

    Sometimes, astigmatism is caused not by the curved cornea, but rather the lens, which has been shaped abnormally, which causes the light rays to curve abnormally and disperse before reaching the retina. Astigmatism occurs when the corneas shape is stretched more like an oval or a soccer ball. Astigmatism occurs when the cornea or lens has a sharper curve in one direction compared to another.

    • Astigmatism is typically present at birth, resulting from the eye form. Astigmatism of just one eye can lead to a lazy eye (amblyopia) if it is present at birth. Unbalanced astigmatism – the difference between two eyes – may cause lazy eyes.
    • Astigmatism can occur from eye injuries, scarring, or surgery on your eyes, especially if your corneal surface is damaged. It also may occur because something is pressing on the corneal surface continuously (such as a large bump on an eyelid) that is pushing it out of its proper shape.
    • Rarely, a condition called keratoconus causes astigmatism, making the clear front of your eye (your cornea) thinner and more cone-shaped.

    2. Causes of Myopia

  • Nearsightedness – It is a refractive error. This problem occurs when the shape or condition of the cornea — or the shape of the eye itself — results in an inaccurate focusing of the light passing into the eye.
  • Genetics. Nearsightedness tends to run in families. If one of your parents is nearsighted, your risk of developing the condition is increased. The risk is higher if both parents are nearsighted.
  • Prolonged close-up activities. Prolonged reading or other close-up activities are associated with an increased risk of nearsightedness.
  • Screen time. Studies have shown that children who use computers or smart devices for long periods have a greater risk of developing nearsightedness.
  • Environmental conditions. Some studies support the idea that a lack of time spent outdoors may increase the risk of nearsightedness.
  • Astigmatism vs. Myopia: How Is It Diagnosed?

    Myopia –

    Myopia can be diagnosed during a general eye exam by a:

    • Visual acuity test to measure vision at distances
    • Refraction test to determine the correct prescription for glasses
    • Slit-lamp exam to assess the structures of the eyes

    Astigmatism –

    Astigmatism is diagnosed with an eye exam. A complete eye exam involves both a series of tests to check eye health and a refraction, which determines how the eyes bend light. Your eye doctor may use various instruments, aim bright lights directly at your eyes and ask you to look through several lenses. Your doctor uses these tests to examine different aspects of your eyes and vision and to determine the prescription needed to provide clear vision with eyeglasses or contact lenses.

    Astigmatism vs. Myopia: Related FAQs

    Have more doubts regarding the eye condition? Here’s a few frequently asked questions.

    Q1. Is Myopia Worse Than Astigmatism?

    The signs of astigmatism and myopia can be similar in that they will both result in blurry or distorted vision. However, myopia occurs when objects far away appear blurred, while astigmatism will also make it more difficult to distinguish certain shapes.

    Q2. Can We Prevent Myopia?

    Spending time outdoors during childhood, adolescence and the early adult years may decrease the risk of developing nearsightedness. Dual focus contact lenses. A type of dual focus contact lens has shown some effect in slowing progression of nearsightedness

    Q3. What is High Myopia?

    People with high myopia have longer eyes (axial elongation), which means that the retina is more stretched and therefore prone to peripheral retinal tears.

    Q4. Can You Have Myopia And Astigmatism?

    Yes, Astigmatism may occur in combination with other refractive errors, which include: Nearsightedness (myopia).

    Summary

    Astigmatism is a vision condition that can cause blurry vision, especially when the room is dim. It can also increase the risk of eye infections and eye diseases such as cataracts. Myopia is considered an eye disorder. It is an optical condition where the eyes are too long and focus light in front of the retina. While there are many reasons why people develop it, most are hereditary. While myopia is usually considered a medical condition, you can also develop it through excessive staring at objects that are far away from you. It’s important to know the difference between astigmatism and myopia, because they are two separate eye conditions that can cause vision problems. Understanding the differences between these eye diseases can help you get the right treatment.

    Blurry vision and unclear sight leading to havoc? Consult with an eye specialist today.

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