Contrast Sensitivity Test

Contrast Sensitivity refers to the visual system's ability to distinguish the luminance difference between an object and its background. It is different from what we usually call "visual acuity" (how small of a letter you can see on an eye chart). A person may have standard 20/20 vision but low contrast sensitivity.

In daily life, contrast sensitivity is very important. For example, when driving in fog, dusk, or rainy nights, or when reading faded text, we rely on high contrast sensitivity to distinguish the outlines of objects. If this ability declines, even with glasses of the correct prescription, things may look "washed out" or lack depth.

In this test, you will see a classic "E" optotype. As the level increases, the color of the "E" will become closer to the pure white background, gradually reducing the contrast. You need to identify the direction of the "E" opening as accurately as possible. If you find it difficult in the early levels, it may indicate potential eye health issues such as cataracts, glaucoma, or optic neuropathy, and it is recommended to consult an ophthalmologist promptly.