This study investigates whether a lighting environment designed for both work phases and rest phases, as well as their transition phases, can induce micro-refresh (MR) and support sustained intellectual concentration during office work. Seven participants performed cognitive tasks under two conditions: one with switching between task lighting and bright ambient lighting using fade-in, and one without the switching. Results showed that Concentration Time Ratio (CTR) improved in four participants and was slightly higher on average with lighting changes. Subjective evaluations indicated reduced fatigue, suppressed decline in concentration, and enhanced refreshment under the lighting-change condition. Participants generally evaluated the lighting environment as comfortable, with appropriate switching frequency and duration. However, individual differences were observed, and some participants did not utilize MR periods as intended. These preliminary findings suggest that dynamic lighting changes may promote refreshment and sustain concentration, though further studies are needed for validation.