Shadowless operation lights are used to illuminate the surgical site to optimally view small, low-contrast objects at different depths in the incision and body cavity. Since the operator's head, hands, and instruments may interfere with the shadow of the surgical site, the surgical shadowless lamp should be designed to minimize shadows and minimize color distortion. In addition, the shadowless lamp must be able to continue working for a long time without emitting excessive heat, which would make the operator uncomfortable and dry the tissue in the surgical field.