Can astigmatism be under-corrected?

　　Astigmatism refers to a condition in which parallel light rays entering the eye from beyond 5 meters fail to converge into a single focal point on the retina after passing through the eye’s refractive system; instead, they form a focal line. Astigmatism is categorized into regular and irregular types. Regular astigmatism can be corrected with eyeglasses, whereas irregular astigmatism cannot.

　　Can astigmatism be under-corrected?

　　Full correction of astigmatism is not always necessary. If adding the full measured astigmatic power achieves best-corrected visual acuity of 1.0 and causes no discomfort during wear, that prescription is considered sufficient. However, if visual acuity reaches normal levels without incorporating the full astigmatic correction, then full correction may not be required. This determination must be made by a qualified optician following a thorough lens insertion (refraction) test. Therefore, individuals with astigmatism should visit a reputable hospital or clinic for professional eyeglass fitting.

　　Pay attention to diet—especially during adolescence. Avoid picky eating, as it may lead to nutritional imbalance and negatively affect vision. Consume foods rich in beta-carotene and zinc to enhance ocular resistance and accommodative capacity. When reading, ensure appropriate lighting—not too dim nor excessively bright. Insufficient illumination impairs visibility, while overly intense light may cause glare and eye strain. Also avoid reading while lying down. Furthermore, pay attention to font size during reading and writing: excessively small print may elevate intraocular pressure.

　　In daily life, cultivate healthy habits regarding both lifestyle and diet. We hope this response proves helpful to you.