Do you sometimes find things a little blurry, unclear, or even a little stretched? Especially when driving at night, do you see a halo around the headlights of the car in front of you? Do you get a headache after a while while reading a book or newspaper, watching TV, or working on the computer? Do your eyes feel tired? If you have experienced one or more of these, this article will be very important for you. Today we are talking about a condition called 'Astigmatism', which many people have, but when they hear the name, they fear it as a serious disease, but it is actually very simple to correct.
What exactly is astigmatism?
Simply put, astigmatism is a condition in which your eye, specifically the transparent part at the front of your eye, the cornea, is not perfectly round like a ball. We all have this condition to some degree.
Imagine a healthy eye that is perfectly round, like a volleyball. Then the light entering the eye is bent in the same way, uniformly, and focused on the same spot on the retina. Then we can see everything very clearly.
But what happens if your eye is shaped like a rugby ball? The light that enters your eye is bent in one direction and in the other. This means that only one part of an object is in focus, while the other part is out of focus. As a result, things look blurry and stretched.
Astigmatism often occurs together with myopia or nearsightedness or hyperopia or farsightedness. We call all three of these conditions refractive errors. This is because all three of them involve a change in the way light entering the eye is bent (refracted).
But don't worry, this is something that an eye doctor can easily fix with glasses, contact lenses, or surgery.
What are the symptoms of astigmatism?
You may have one or more of these symptoms:
- Things appear blurry or distorted (e.g., a circle appears oval)
- Eyestrain
- Frequent headaches
- Trouble seeing at night
These symptoms develop gradually. You won't notice a big difference right away. The headaches come from the effort your eyes have to put in to focus on things. Experts also believe that this condition runs in families . This means that if your mother, father, or someone in your family has it, you are more likely to develop it.
What are the reasons for this situation?
For many people, this condition is something they are born with. But experts still don't know exactly what causes it. Apart from that, astigmatism can also occur for other reasons.
- After an eye accident
- Due to an eye condition
- After eye surgery
Very rarely, astigmatism can also be caused by a condition called keratoconus. This is when the cornea of the eye becomes thinner and cone-shaped. In this case, contact lenses are needed to see clearly.
But remember one thing. Reading books in dim light or watching TV too close does not cause astigmatism. That's just a misconception in society.
How do you find this, Doctor?
If you notice any changes in your vision, be sure to see an eye doctor for a complete eye exam. The doctor will have you read an eye chart to see how sharp your vision is. In addition, they use various instruments to accurately measure this condition.
- Phoropter: You remember, the machine that changes lenses one by one and asks, "Is this clear, is that clear?" That's how you find the lens that gives you the clearest vision.
- Keratometer: This machine measures the curvature of your cornea. This gives the doctor a good idea of the shape of the cornea and its ability to focus light.
- Autorefractor: This device sends light into your eye and measures how it bounces back. This can give you a rough idea of what lenses you need.
- Corneal topographer: This is the most detailed way to get information about the shape of the cornea. This creates a three-dimensional (3D) color map of your cornea. This test is very important if you are having laser surgery (such as `LASIK`).
Can we understand your prescription?
When you see the letters and numbers on the prescription your doctor gives you, you might be wondering what these are. Let's explain it simply.
| Symbol / Part | Meaning |
|---|---|
| OD and OS | OD stands for the right eye (Oculus Dexter), OS stands for the left eye (Oculus Sinister), and OU stands for both eyes (Oculus Uterque). |
| First number (Spherical) | This tells you whether you have a problem with near or far vision. If there is a minus sign (-) in front of the number, you are nearsighted. If there is a plus sign (+) in front of the number, you are farsighted. The higher the number, the more blurred your vision becomes. |
| Number two (Cylindrical) | This is how much astigmatism you have. The higher this number, the more astigmatism you have. |
| Third number (Axis) | This tells you the location of the astigmatism in your cornea. |
For example, if a prescription says "OD -1.00 x -2.00 x 155", that means your right eye (OD) has 1 diopter of nearsightedness and 2 diopters of astigmatism, at a position of 155 degrees.
What are the treatments for this?
Almost all cases of astigmatism can be corrected with glasses or contact lenses. However, if you have very little astigmatism and no other vision problems, you may not need glasses.
Glasses
Contact lenses are designed to reduce the blurring caused by the irregular shape of your cornea. They work well when you are looking straight ahead. However, if you have a high amount of astigmatism, objects like the floor and walls may appear slightly stretched when you first put them on. Don't worry about that. Your eyes will adjust to it over a few days or weeks. Try wearing them for a few hours in the morning and gradually get used to them. However, if your vision doesn't improve, see your doctor again to make sure your prescription is correct.
Contact Lenses
Contact lenses can also correct this condition. But you need a special type of lens designed for that purpose. Soft lenses used for astigmatism are called toric lenses. These are designed to rotate the eye back into the correct position even when it is tilted.
If your astigmatism is severe, rigid gas-permeable contact lenses are best. Sometimes doctors use these rigid lenses in a treatment called orthokeratology. In this, you wear these lenses while you sleep at night. The lenses temporarily correct the shape of your cornea. You can see clearly throughout the day. But you have to wear these lenses continuously to maintain that shape.
Laser Eye Surgery
Laser surgery, such as `LASIK` or `PRK`, permanently changes the shape of your cornea to focus light properly. These can produce very good results. You can ask your eye doctor for more information about this.
Does this situation happen to young children too?
Yes. Many babies are born with astigmatism. But it's nothing to worry about. It usually goes away on its own by the time they're about a year old.
But the most important thing is that if a child's vision problem is left untreated, it can directly affect his schoolwork. A young child may not understand that he has a problem with his vision. Therefore, this can also affect his schoolwork. Sometimes , he may be wrongly labeled as a 'learning disabled child'. Therefore, it is very important to have a child's eyes checked. It is best to have an eye exam when the child is about 6 months old.
Take-Home Message
- Astigmatism is not a disease, but a visual defect that occurs because the shape of the cornea of the eye is not perfectly round.
- The main symptoms are blurred vision, blurred vision, headaches, and difficulty seeing at night.
- This condition is often congenital and is not caused by habits such as reading in dim light.
- There are very effective treatments for this, such as glasses, contact lenses, and laser surgery.
- If you suspect that you or your child has a vision problem, see a qualified eye doctor without delay.
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