How many diopters of myopia require wearing corrective glasses?

Eyeglass fitting involves several steps: refraction testing, lens selection, frame selection, lens edging, and assembly. Refraction testing is best performed in the morning, as this enhances accuracy. Lens materials are primarily glass or resin, while frame materials are predominantly plastic or metal. During fitting, a lens edger is typically used to adjust the lens shape so that it precisely matches the inner contour of the frame. So, at what degree of myopia should one begin wearing corrective eyeglasses? Below, we address this question.

At What Degree of Myopia Should One Wear Eyeglasses?

Under normal circumstances, individuals with myopia exceeding −2.00 diopters (D) generally require corrective eyeglasses. When myopia exceeds −2.00 D, visual acuity becomes noticeably blurred, interfering with daily activities and work performance. Failure to wear appropriate corrective lenses may lead to ocular fatigue, potentially accelerating the progression of myopia. Therefore, individuals with myopia greater than −2.00 D should wear properly prescribed eyeglasses. However, they should also practice proper eye hygiene—such as avoiding prolonged near work and performing regular eye massages—to help maintain ocular health. For mild myopia causing only minimal visual impairment, corrective lenses may not be necessary. Conversely, if high myopia significantly reduces uncorrected visual acuity and impairs normal work, study, or daily life, timely prescription and consistent wear of corrective eyeglasses are strongly recommended. Generally, sustained, full-time wear is advised for myopia exceeding −2.00 D.

Knowledge Extension: How to Prevent Progression of Myopia

1. Eye Exercises

Performing regular eye exercises helps alleviate eye strain. Acupressure on key points such as the temples (Taiyang) and Jingming acupoint can effectively improve ocular blood circulation and thus relieve myopia symptoms. Additionally, consuming foods rich in vitamin A and protein—such as carrots, milk, and eggs—supports ocular recovery. Furthermore, frequent circular eye movements (“gaze rotation”) are highly beneficial for vision restoration.

2. Distance Gazing

Gazing into the distance helps regulate the eye’s crystalline lens. Thus, when myopia develops, regularly focusing on distant objects relaxes the ciliary muscle and alleviates eye fatigue. Similarly, viewing green plants can ease visual strain: because green light has a relatively short wavelength, its focal point lies slightly anterior to the retina, thereby promoting natural relaxation of the eye and facilitating visual recovery.

3. Maintaining Proper Posture

Many factors contribute to declining vision, but improper visual habits—especially prolonged near work—are among the most common causes. Therefore, avoid squinting during reading or screen use; maintain an optimal viewing distance of 30–40 cm between eyes and reading material; refrain from reading while lying down; and take frequent breaks to gaze into the distance to support visual recovery. Another helpful technique is controlled “gaze rotation”: relax the body, keep the head still, slowly rotate the eyes downward, then leftward, upward, rightward, and back to center—repeating this sequence regularly strengthens the extraocular muscles and promotes visual rehabilitation.

The above outlines the general guidelines regarding the myopia threshold requiring corrective eyeglasses. We hope this information proves helpful to you.