Friday, 4 July 2014

Student Alertness Increases Under LED Lighting

A study conducted by Fagerhult’s lighting academy found student’s alertness (caused by the hormone cortisol) was boosted by increasing LED light levels.

Although these findings are novel for LED lighting, the link between alertness and lighting levels had already been established in a 2009 study using T5 fluorescent luminaires. The work conducted with fluorescent luminaries showed cortisol levels in student’s blood increased when exposed to boosts of a high luminance in the morning and early afternoon. Results from the 2009 study showed increased fluorescent light levels saw students’ performance rise by one grade on average during the darkest part of the year.

Henrik Clausen, director of the Fagerhult Lighting Academy said: “People started asking whether LED lighting would have the same effect as T5 so we had to repeat our research.”

This latest study measured the hormone levels of students at a university in Sweden, researchers found student’s cortisol levels increased in LED lit environments with luminance levels of 100cd/m2, mirroring the results of the 2009 study. When asked about the results, Henrik Clausen said: “Actually the pupils’ cortisol levels raised a little bit faster with LEDs that they did with fluorescent lamps. It’s probably because there is an inherent peak of blue light in LEDs, but we don’t know that for sure.”

The research facility is now looking at students’ grades to see if the improved hormone levels results in better academic performance, but has not yet proven a correlation in the LED-lit classrooms.


When speaking at the International Lighting Fixture Design conference in London last week, Clausen cautioned that the research should not be applied too widely: “If you want to do research you have to choose a path and we chose to focus on classroom lighting, so we don’t claim that this approach works for everything”.