An instrument that measures how well the eye adapts to changes in light intensity, particularly used in vision testing.
From Latin 'adaptare' (to adapt) plus Greek 'metron' (measure), a scientific instrument name created in the 20th century.
An adaptometer reveals something amazing: your eyes have different sensitivity settings, and the adaptation process is so fast you never notice it—you just think the world stays the same brightness when you move between sunlight and shadow.
Complete word intelligence in one call. Free tier — 50 lookups/day.