The present invention relates to a treating method for hair growth inhibition, which comprises administering the extract of a plant of the family Juniperus or a malt. The method for detecting an accident obtains an image from a predetermined region on a road, determining whether there exists an accident or not depending on change transition of gray levels for pixels on a line type trap set in advance on the basis of the obtained image. The first optical element is adapted to move along the optical axis of light from the laser source. When the body is disposed in the sliding groove, the first engaging part is engaged in the first engaging groove.