What Is the Difference Between Astigmatism and Myopia?
Jun 29, 2022
Source: Cainiu Health
Dr. Chen You
Introduction
The differences between astigmatism and myopia lie in their distinct causes, symptoms, and stability. Astigmatism is related to irregular curvature of the cornea, whereas myopia results from light focusing in front of the retina. Their symptoms also differ: typical symptoms of astigmatism include ghost images (double or blurred vision), while myopia is primarily characterized by clear near vision but blurry distance vision. Additionally, the two conditions differ in terms of stability.
When many people feel their vision is blurry, they often assume it’s simply due to myopia. However, if you visit an ophthalmology clinic for a vision examination, you may discover that you have some degree of astigmatism. Only by distinguishing between astigmatism and myopia can vision be corrected more effectively. So, what are the differences between astigmatism and myopia?
What Are the Differences Between Astigmatism and Myopia?
The differences between astigmatism and myopia lie in their underlying causes, symptoms, and stability. Astigmatism arises from irregular curvature of the cornea (or, less commonly, the lens), whereas myopia results from light focusing in front of the retina due to excessive axial length or refractive power of the eye. Their symptoms also differ: the hallmark symptom of astigmatism is “ghosting” — seeing multiple blurred images of a single object — while myopia is primarily characterized by clear near vision but blurry distance vision. Additionally, the two conditions exhibit different degrees of stability. In astigmatism, vision gradually declines, and patients consistently experience overall blurriness; however, the most distinctive symptom is ghosting — for instance, perceiving a single point as multiple points. In contrast, myopia also leads to decreased visual acuity and blurriness, but it does not cause double or multiple images. Individuals with myopia can see nearby objects clearly, yet distant objects appear significantly blurred.
Astigmatism requires corrective eyewear. Like myopia and hyperopia, astigmatism is a type of refractive error that impairs visual acuity. It occurs when the eye’s optical system fails to focus incoming light precisely onto the retina due to irregularities in the shape of the cornea or lens at specific meridians. Once diagnosed via refraction testing, astigmatism can be accurately corrected with spectacles prescribed for a specific axis, thereby restoring normal visual acuity. Because astigmatism tends to cause greater visual fatigue, wearing corrective lenses and minimizing prolonged visual strain can help prevent progressive worsening. For adults with stable, low-degree astigmatism (≤6 diopters), laser refractive surgery may also be a viable option for vision correction.
If you notice any symptoms suggestive of these conditions in daily life, seek prompt medical evaluation and actively cooperate with your doctor’s treatment plan. We hope this information has been helpful to you.
