When purchasing new eyewear, most people focus on frame style, lens color, or UV protection. However, one of the most critical yet overlooked parameters is eyeglasses transmittance. Transmittance refers to the percentage of visible light that passes through a lens to reach your eyes. Higher transmittance means clearer, brighter vision, while low transmittance can cause eye strain, poor night vision, and a dim viewing experience. In this comprehensive guide, we will explore everything about eyeglasses transmittance, why 90% light transmittance eyeglasses represent the gold standard for optical clarity, how optical lens transmittance is measured, what affects eyewear transmittance rate, and the unique benefits of PC lens high light transmittance eyeglasses. By the end, you will be able to choose lenses that maximize both comfort and visual performance.