Introduction
It’s not clear why some people are born with astigmatism, but it may have a genetic component. It can also be caused by eye injuries, certain surgeries, or the degenerative condition keratoconus.
Eye care specialists can diagnose astigmatism during an eye exam. They’ll use a device called a phoropter to test your vision by having you look through different lenses and asking which ones make it clearer.
What is Astigmatism
Astigmatism is a common eye condition caused by subtle flaws in the way your cornea and lens refract light. Normally, the eye’s symmetrical cornea and lens bend light evenly so that it focuses in one spot on the retina at the back of your eyeball. This creates nerve impulses that your brain interprets as visual images. But with astigmatism, the irregular curvature of your cornea or lens prevents light from focusing clearly on the retina.
Your doctor can diagnose astigmatism during a comprehensive eye exam. He or she will conduct a series of tests to measure your vision, including a visual acuity test and a refraction test with a phoropter. Your doctor may also perform a corneal topography scan or use a keratometer to determine the shape and curve of your cornea.
Eyeglasses and contact lenses can correct astigmatism by refocusing light onto the retina. You may need a special contact lens called a Toric soft or RGP (rigid gas permeable) lens depending on the severity of your problem and the amount of correction you need. If you have this problem, it is important to wear your eyeglasses or contacts regularly to help prevent the symptoms of astigmatism from worsening. Your doctor may suggest eye surgery to treat astigmatism if it is severe or causing other health problems.
Symptoms of Astigmatism
Eye doctors can detect this issue in children because it typically happens alongside myopia (nearsightedness) and hyperopia (farsightedness). Children with astigmatism might have difficulty reading or concentrating. They may also experience blurry vision when trying to focus on close or distant objects. Light rays in the eye must hit a single focal point to create sharp images. If the eye is misshaped, astigmatism can cause distorted vision that makes objects appear shadowy or ghost-like.
Your eye doctor can diagnose astigmatism during a comprehensive eye exam. They will measure your visual acuity by having you read letters on an eye chart and may use a tool called a keratometer to determine the curvature of your cornea.
The irregularity in your eye’s shape can make it hard for your lens and cornea to bend light correctly (a process called refraction) and transmit clear, focused vision to the back of your retina. The brain then processes the signals from the retina into a clear image. Your eye doctor can prescribe corrective lenses to help you see clearly and easily. These can be in the form of eyeglasses, contact lenses, or laser surgery, such as LASIK. Some types of laser surgery can even fix astigmatism by reshaping the cornea permanently. However, mostly it can be corrected with prescription eyeglasses or contacts.
How to treat it
In eyes without astigmatism, the smooth cornea and lens focus light rays to a single point on the retina (the thin layer of light-sensitive tissue that lines the back of the eye). With this problem, the light rays don’t come to a single point on the retina, and the result is blurry vision.
Eyeglasses correct this issue by reshaping the cornea and lens so that they have a more rounded appearance. There are many types of eyeglasses, and your eye care professional can help you choose the right frames for your face and style preferences. You can also wear contact lenses that are specifically designed for astigmatism, including hard and soft options. These contacts can be worn overnight and removed when you wake up, to slightly reshape your cornea and allow for clearer vision. Another option is orthokeratology, which uses specially designed contact lenses to temporarily reshape your cornea and allow you to see clearly without glasses or contacts.
Astigmatism can be present at birth, or it may develop due to eye surgery, illness, or injury. It can also occur in combination with other refractive errors such as nearsightedness or farsightedness, and it may worsen with age. There is no way to prevent this problem, but regular eye exams and appropriate treatment can help manage symptoms.
Frequently Asked Questions (FAQs)
Q1: Can astigmatism worsen over time?
A1: Astigmatism typically remains stable over time. However, certain factors like eye growth during childhood or changes in the cornea’s shape can cause fluctuations. Regular eye examinations can help monitor any changes in astigmatism.
Q2: Can astigmatism be corrected permanently?
A2: Refractive surgery, such as LASIK or PRK, can provide long-term correction for astigmatism. However, individual results may vary, and it is important to consult with an experienced eye surgeon to determine eligibility and discuss potential risks and benefits.
Q3: Can astigmatism cause headaches?
A3: Yes, it can cause eyestrain and headaches, especially when the eyes have to work harder to focus on objects due to the irregular corneal shape. Correcting astigmatism with prescription eyeglasses or contact lenses can alleviate these symptoms.
Q4: Can astigmatism affect children?
A4: It can affect individuals of all ages, including children. Early detection and correction are crucial to ensure proper visual development and academic performance.
Conclusion
Astigmatism is a common vision condition that can cause blurred or distorted vision at various distances. By understanding the causes, symptoms, and available treatment options, you can actively manage it and maintain good eye health. Regular eye examinations and consultation with eye care professionals are essential for effective diagnosis and treatment of astigmatism.