With the transition from natural lighting to artificial lighting, humans tend to spendmore and more time in indoor environments. The increased time spent indoor has aneffect on humans’ health, mood, and performance. This study explores how artificiallight designed to imitate daylight can impact student’s alertness and comfort in anindoor environment with limited access to daylight. Through the testing of two differentlighting designs, the student’s subjective fatigue and perception of comfort wereevaluated in a windowless room at KTH’s library. The surveys and measurementsshowed considerable improvements in alertness and comfort when the lightingimplemented was illuminating the space through a dynamic, uniform wall illuminanceon a 4000k colour temperature. The results show clearly that the students are affectedby the lighting implemented, however it can not be attributed to the CCT, intensity oreven uniformity as they were confounded. It suggests that an artificial lighting followingsome daylight qualities (dynamic and indirect) enhances alertness and comfort.