Surgical shadowless lamps are used to illuminate the surgical site and observe small, low-contrast objects at different depths in the incision and body cavity. Because the operator's head, hands, and instruments can cause disturbing shadows to the surgical site, the surgical shadowless lamp should be designed to eliminate dark shadows as much as possible and reduce color distortion to a low level.

In addition, the shadowless lamp must continue to work for a long time without emitting excessive heat, because overheating will make the surgeon uncomfortable, and will also make the arrangement in the surgical area boring, and the surgical shadowless lamp is one of the important medical equipment in the operating room. Surgical shadowless lamps generally consist of single or multiple lamp heads, which are attached to a cantilever and usually attached to a fixed combiner. It rotates around it and has automatic braking and stopping functions. The handle with disinfection and sterilization function can be flexibly positioned, which makes it easier for the physician to adjust the orientation of the light source according to the specific situation during surgery. During surgery, the doctor's head, hands, and instruments may cause disturbances to the surgical site.

Therefore, surgical shadowless lamps are needed to help eliminate these shadows and minimize color distortion to avoid interfering with the doctor's judgment. Under normal circumstances, when light hits an opaque object, a shadow is produced, and the deep shadow in the middle is called umbra, and the part around it that gradually becomes lighter is called penumbra.