Astigmatism is a refractive error caused by an irregular curvature of the cornea, leading to blurred vision due to improper light focus on the retina. It can be classified into myopic, hyperopic, and mixed types, and is diagnosed using visual acuity tests, keratometers, and autorefractors. Treatment options include toric contact lenses and refractive surgery like LASIK to reshape the cornea.

1. The Ultimate Guide
to Astigmatism
theviewoptique.com

2. Astigmatism is a problem caused by the curvature of your cornea. This makes it harder for your eye to focus light onto your retina, which
distorts and blurs your vision. Toric contact lenses are a simple solution for astigmatism, which is not too severe.
What is Astigmatism?

3. Types of Astigmatism
1. Myopic Astigmatism
When one or both of the main meridians of the eye are shortsighted.
2. Hyperopic Astigmatism
When one or both of the main meridians of the eye are farsighted.
3. Mixed Astigmatism
When one of the main meridians of the eye is shortsighted, while the other is longsighted,
which is known as mixed astigmatism.

4. Causes of an Astigmatism
● A flawed corneal structure is the cause of corneal astigmatism.
● Lenticular astigmatism occurs when the lens is made improperly.
● Corneal surface modification during eye surgery
● The cornea may change shape as a result of the
● Eye disorders keratoconus and keratoglobus.
● Issues that could impact the eyelids and distort the cornea include a big stye or a clogged oil gland.

5. How to Test Your Astigmatism?
First, your visual acuity will initially be evaluated using a letter chart to ascertain how sharp your vision is. Your eyes will then be placed in
front of a variety of lenses so you can assess how well they focus.
Second, The next step is to utilize a Keratometer to measure the cornea's curvature; if needed, corneal topography can be performed to
provide an even more thorough analysis of your eyes
surface.

6. What Could an Astigmatic Individual See?
If you have astigmatism. When the vertical meridian is steeper, staring at vertical lines will impair your vision. Direct astigmatism is what
is meant by this.
If your horizontal meridian, which is also referred to as indirect astigmatism, is harmed, your eyes won't be able to focus on horizontal lines,
which will once again cause blurry vision.

7. What Exactly Qualifies As High Astigmatism?
The numbers on your prescription for contact lenses or glasses indicate whether you have high astigmatism. In general, the stronger your
astigmatism is, the higher the axis and cylinder numbers on your prescription are.

8. Does Astigmatism Affect How People See Light?
The degree of astigmatism a person has may affect how they perceive light. Your cornea is shaped like a rugby ball if you have
astigmatism, which causes light to bend unevenly and cause visual distortion.

9. Symptoms of Astigmatism
● Headaches
● Eye weariness, particularly behind the eyes
● Irritation in the eyes
● Darkness and blindness

10. Astigmatism Diagnosis
● 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.

11. Why Does Astigmatism Get Worse At Night?
Astigmatism is worse at night or in low light because your eyes widen to receive more light, which increases the likelihood of glares,
haloes, and fuzzy or distorted vision. It's critical to find out if it's safe for you to drive at night from your eye doctor because streetlights and
taillights could appear hazy.

12. Can You Wear Regular Contacts if You Have Astigmatism?
Toric contact lenses are often the most practical and efficient technique to treat astigmatism as compared to costly corrective surgery.
They differ from ordinary contact lenses in that they are torus-shaped rather than spherical, more resembling a slice of a ring doughnut
than a portion of a football.
Rigid gas permeable lenses that are toric can only be used to correct irregular astigmatism; toric contact lenses are normally soft lenses.

13. Does Astigmatism Get Worse With Age?
Age may make astigmatism worse, though this isn't always the case. Direct astigmatism usually turns into indirect astigmatism as people
age. As we age, the pressure that our eyelids normally apply on the cornea decreases, and as a result, the steepness of the vertical meridian
curve
also decreases. Direct astigmatism turns to indirect astigmatism, which may progressively worsen, as the horizontal meridian curve gets
worse.

14. 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.

15. References
https://blog.theviewoptique.com/post/2022/11/14/the-ultimate-guide-to-astigmatism
https://www.aao.org/eye-health/diseases/what-is-astigmatism
https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/astigmatism?sso=y
https://www.britannica.com/science/astigmatism-eye-disorder