« Back to Glossary Index

What is Lux?

A lux is a unit of illuminance. More specifically, one lux equals one lumen per square meter.

Understanding Lux Vs. PAR

  Manufacturers have little to say about lux or lumens when discussing grow lights. This is because lux measures the intensity of light visible to the human eye. However, the wavelengths that plants use for photosynthesis are less visible to our eyes. So instead of boasting about illuminance, grow light manufacturers emphasize the amount of PAR—or photosynthetically active radiation—given off by their lights.