A light-activated illuminating member having a support member and a phosphorescent material supported thereby. The phosphorescent material can form a luminescent image having a varying luminescent effect after the phosphorescent material is exposed to a light of constant intensity. One or more such light-activated illuminating members can be assembled with a light source, such as a UV-LED pen, and be formed into a book-type writing/drawing toy which is capable of providing a varying luminescent effect. When a plurality of such illuminating members are used in the book-type toy, such a toy is capable of providing a different, combined luminescent effect.