This work aims to investigate the correlation of the impact of lighting on circadian rhythm, and the impact of lighting in emotions (arousal and valence) in real and virtual environments by using an electroencephalogram (EEG) test, which is a reliable and cost-effective methodology used to measure brain activity. Using EEG, the emotions of the user can be recognized by analyzing the different brain signal waves generated accordingly. A sample size of 15 participants was recruited for the study in an office space, where participants were exposed to daylight and electrical lighting, and were asked to perform practical activities. To measure the effects of lighting, brain activity was continuously measured with an EEG helmet, and the melanopic equivalent daylight illuminance (EDI) was measured at the eye level, with a spectrometer in the real environment and with ALFA software in the virtual reality. Additionally, a questionnaire using the Self-Assessment Manikin (SAM) approach was provided to participants to assess the subjective levels of valence and arousal, in order to cross check and validate the EEG data. The study design aimed to find the correlations between the melanopic EDI and the increase/decrease in alpha, beta, and gamma brain waves, which are connected to high/low valence and arousal (also cross checked with the questionnaires). Correlations between the melanopic EDI, brain activity, and emotional states, could provide valuable insights for designing environments that promote optimal circadian health and emotional well-being. This work also compares the results between real and virtual environments to validate how VR could be a valuable tool not only to display an upcoming space and light setting but also bring the experience even further closer to reality by mimicking the emotional response.