How many degrees of vision constitute myopia?

In general, myopia is diagnosed when the refractive error reaches or exceeds 100 degrees. Clinically, the severity of myopia is categorized based on the degree of refraction. The specific analysis is as follows:

Myopia occurs when parallel light rays focus in front of the retina, causing blurred vision. The exact degree can be determined through optometric examination. Myopia between 100 and 300 degrees is classified as mild; patients typically experience blurriness when viewing distant objects such as road signs or writing on a blackboard, while near vision remains largely unaffected. Myopia ranging from 300 to 600 degrees is considered moderate, affecting both near and far vision to some extent, and prolonged eye use may lead to symptoms like eye strain and dryness.

During childhood and adolescence, eye axis development is not yet stable. Even a refractive error around 50 degrees might indicate pseudomyopia rather than true myopia. This condition is often caused by ciliary muscle spasm and may improve with eye relaxation and better visual habits, potentially restoring vision. Therefore, diagnosis should not rely solely on refractive degree but must include cycloplegic refraction to differentiate accurately.

In daily life, it's important to develop healthy visual habits, avoid prolonged close-up screen time, and take breaks by looking into the distance every 40 minutes or so. Regular vision check-ups help monitor changes promptly, enabling timely and scientific interventions to slow the progression of myopia and protect eye health.