The prospect‐refuge theory is a theory of landscape aesthetics and has recently been applied to interior design. The purposes of this article were to apply the prospect‐refuge theory to the interior lighting environment and to examine the effects of nonuniform lighting on the evaluations of a room shared with another person. Two experiments were conducted: Experiment 1 focused on the situation without conversation, and Experiment 2 on the situation with conversation. The results showed that nonuniform lighting influences the features of prospect and refuge in rooms. The results also showed that the features of prospect and refuge are important when the space is shared with people having no interaction. However, when people have an interaction, a sense of unity, which is formed by illumination wrapping them together, is important to make an adequate environment.