Abstract: Various combinations of different optical features in a microlens screen are disclosed. In one arrangement, a screen is provided for depixelating purposes, comprising an array of transparent rectangular portions (14) in a light diffusing field (20) formed by minute closely packed microlenses of a graded refractive index type. In another arrangement, a screen formed with an array of integral graded refractive index lenses has surface refractive index lenses additionally provided by part-spherical embossments on a surface of the screen, the embossments being of one or more orders of magnitude greater in diameter than the graded refractive index lenses. There are also disclosed techniques for preventing light transmission through a microlens screen except through the microlenses, the use of microlens screens to improve the performance of solar panels and microlens screens conforming to a part-spherical surface.