The light-induced modification of mechanical and optical properties of several amino- styrene-containing polymers has been investigated. The nano- and microindentation techniques were used for determination of mechanical parameters. The variable-energy positron annihilation spectroscopy (slow-positron beam technique) was developed to measure defect depth profiles in the near-surface region. The increase of S-parameter with the increasing of nanohardness and elastic modulus were determined for these materials.