Astigmatism
Astigmatism is a common vision condition that occurs due to an irregular shape of the cornea or, in some cases, the curvature of the lens inside the eye. This irregular shape prevents light from focusing properly on the retina, leading to blurred or distorted vision at any distance. Other symptoms may include eyestrain, headaches, and difficulty driving at night.
Astigmatism can occur in combination with other refractive errors like nearsightedness (myopia) or farsightedness (hyperopia). It is usually present from birth and can change in severity over time.
Astigmatism is diagnosed through a comprehensive eye exam, and it can be corrected with eyeglasses, contact lenses, or surgery. The treatment choice depends on the severity of the astigmatism and the patient's lifestyle and preferences.
What Types of Astigmatism Are There?
There are two main types of astigmatism:
Corneal Astigmatism
This type happens when the cornea, the clear front surface of the eye, has an irregular shape. A normal cornea is spherical like a basketball, but in corneal astigmatism, it may be shaped more like a football, with one axis more curved than the other.
Lenticular Astigmatism
This occurs when the lens inside the eye has irregularities in its shape. Even if the cornea is perfectly shaped, irregularities in the lens can cause light to be focused incorrectly, leading to vision problems.
Astigmatism Symptoms
While astigmatism itself is a refractive error rather than a disease, the visual disturbances it causes can lead to a variety of issues, especially if left unaddressed. Some of the common symptoms or side effects include:
Blurred or Distorted Vision: Vision may be blurry or distorted at all distances.
Eyestrain and Discomfort: Efforts to focus can cause eyestrain and discomfort.
Headaches: Frequent and persistent headaches can occur due to the strain of trying to see clearly.
Difficulty with Night Vision: Seeing in low light or at night can be especially challenging.
Difficulty with Visual Tasks: Tasks requiring sharp vision, like reading or using a computer, may be harder.
Eye Fatigue: The eyes may feel tired after regular activities due to the extra effort needed to focus.
These symptoms of astigmatism can significantly impact an individual's quality of life, especially if the astigmatism is moderate to severe and not corrected with glasses, contact lenses, or surgery. Proper correction can alleviate these symptoms, allowing for clearer vision and reducing or eliminating the associated discomforts.
If you experience symptoms like these, it's important to consult an eye care professional for a comprehensive eye exam to diagnose any refractive errors and discuss appropriate treatment options.
Glasses For Astigmatism
Glasses can help correct astigmatism by providing precise optical correction tailored to the unique irregularities of each eye's shape, this correction is recorded in the form of a prescription. If you have an Astigmatism it is important to book regular eye test to ensure your prescription is up-to-date - this will make sure your glasses provide clear vision.
Astigmatism FAQs
What is astigmatism?
Astigmatism is a vision condition caused by an irregularly shaped cornea or lens. This irregularity prevents light from focusing evenly on the retina, resulting in blurred or distorted vision at various distances, which can affect daily activities like reading and driving.
How is astigmatism corrected?
Glasses can be extremely effective for correcting Astigmatism. Your prescription contains all of the information required to correct your vision. An optician can precisely measure the severity of your astigmatism and prescribe an additional 'cylinder' value alongside the spherical (SPH) component in your prescription.
This cylinder value is added to the spherical value to accurately direct light onto the retina. These two components are oriented at right angles to each other, with the 'axis' value specifying their orientation. The axis, measured in degrees, doesn't reflect the severity of the astigmatism but rather its orientation.
If your prescription includes astigmatism correction, it will list a cylinder value, often denoted as CYL, which represents the degree of astigmatism, and an axis value, which shows the orientation in degrees. Astigmatism can affect either one or both eyes.
What are the symptoms of astigmatism?
Common symptoms include blurred or wavy vision, difficulty seeing clearly at night, frequent eye strain or discomfort, headaches, and squinting. Individuals may also notice that their vision fluctuates, making it challenging to maintain focus.
How is astigmatism diagnosed?
An optician can diagnose astigmatism through a comprehensive eye exam. This typically includes tests that assess visual acuity and measure the curvature of the cornea, allowing the extent and nature of the refractive error to be determined.
Can astigmatism change over time?
Yes, astigmatism can change due to various factors, including age, eye injuries, or surgery. Regular eye exams are essential for monitoring vision changes and ensuring that your prescription remains accurate.
Is astigmatism hereditary?
Astigmatism can run in families, meaning genetics may play a role in its development. If parents have astigmatism, their children may also be more likely to develop the condition.
Can I prevent astigmatism?
While you cannot prevent astigmatism, maintaining overall eye health through regular eye exams and proper eye care can help identify and manage the condition early.
What should I do if I suspect I have astigmatism?
If you experience symptoms like blurred vision or eye strain, schedule an appointment with your optician for a comprehensive exam. Early diagnosis and treatment can improve your quality of vision by getting a corrective prescription.