A method using irradiation with optical light having a wavelength of 160 to 500 nanometers without higher wavelengths with cooling of the surface during the irradiation to modify the surface (12A, 104A, 202A, 304A, 402A, 502A) of a substrate (12, 104, 202, 304, 402, 502) is described. The light is filtered or the lamp (24, 106, 212, 306, 510) is restricted to the limited range to avoid the affects of the higher spectra. The light can be pulsed or continuous. The method is significantly enhanced by the presence of water (14, 124, 204, 306, 410, 508) on the surface, preferably also in the presence of ozone in the water. The treated surfaces are more paintable and bondable.