Abstract: A method for the treatment of skin including the steps of determining the skin depth for energy absorption necessary for treatment; and generating a spot size for energy impinging on the skin to provide a desired amount of energy to the desired depth for treatment. In one embodiment the selected spot size has a small diameter. In another embodiment the spot diameter is narrower than the spacing between adjacent hairs on the skin. In another aspect the invention relates to an apparatus for the treatment of skin including a source of energy; and a means for selecting a spot size for energy from the source impinging on the skin to provide a desired amount of energy to a desired depth for treatment. In another embodiment the apparatus includes an interlock to prevent the laser from producing light unless the source is positioned to irradiate only the skin.