‘验光’ literally means ‘to test light’ — but in medical Chinese, it refers specifically to an eye refraction test, a standard procedure performed by optometrists or ophthalmologists to measure how light bends as it passes through the eye. This test determines whether someone has nearsightedness, farsightedness, astigmatism, or presbyopia, and is essential for prescribing accurate eyeglasses or contact lenses.

The character 验 (yàn) means ‘to examine, test, or verify’, while 光 (guāng) means ‘light’. Together, they form a compound noun used exclusively in clinical and optical contexts. In China, people commonly undergo 验光 before buying glasses — often at optometry clinics, hospital eye departments, or specialized optical stores. It’s a routine, non-invasive assessment that typically involves looking at charts and adjusting lenses until vision is sharpest.