Abstract: An eye-safe light curtain is generated by a plurality of LED's illuminating a cylindrical lens having a corrugated cylindrical surface. A camera generates a first image of an avoidance zone boundary of an air bag inflator with the light curtain off, and a second image of with the light curtain on along the avoidance zone boundary. The first image is subtracted from the second image, and the resulting difference image is binned to enhance signal strength. A penetration of the avoidance zone is classified from features of the leading edge of the binned image, and the air bag inflator is disabled if the avoidance zone is penetrated by an occupant at risk of injury from the deployment thereof. An image of the light curtain may be recovered for high ambient lighting conditions by adapting the exposure time of the camera responsive to the percentage of pixels in a mask region of the first image having values exceeding a threshold.