Definition

The amount of light that reaches a surface, often measured in lux or foot-candles.

Example

The illuminance in the room was bright enough for reading without any additional light.

Conversation

Did you notice how the illuminance in this room changes throughout the day?

Yeah, it makes such a difference in how cozy it feels.

I think natural light really enhances the illuminance of a space.

Absolutely! It’s so much better than artificial lighting.

Synonyms & Antonyms

Root Explanation

Illuminance is formed from "illuminare" (meaning to light up or make bright) and the suffix "-ance" (indicating a state or quality). The word refers to the quality or state of being illuminated or the amount of light that falls on a surface.

Memory Tip

Think of 'lighting up' ('illuminare') to remember that 'illuminance' refers to the quality of light on a surface.

Visually Confused Words