An optical member includes a light source, a first substrate to be a light guide that guides emitted light from the light source, a variable layer in contact with a predetermined surface of the first substrate, and a second substrate facing the first substrate via the variable layer. When a refractive index of the first substrate is n1, a refractive index of the variable layer can be changed to n2 or n3 (where n2 > n3), and n1, n2, and n3 satisfy a relationship of |n1 - n2|