Abstract: Disclosed is a glass material for press forming providing an optical element having a sufficient optical performance without surface cracks, cloudiness, scratches, and the like even when the glass material contains a highly reactive component. Also disclosed are an optical element having a sufficient optical performance without surface cracks, cloudiness, scratches, and the like and a method for manufacturing the same. Specifically disclosed is a glass material for press forming which comprises a core portion composed of multicomponent optical glass and a surface glass layer covering at least a region serving as an optical functional surface of the core portion. The surface glass layer contains more than 90 mass % of SiO2, and the thickness of the layer is less than five nanometers. Also specifically disclosed is a method for manufacturing a glass optical element by heating the glass material and by press forming the softened glass material using a forming die.

Abstract: Disclosed is a glass material for press forming providing an optical element having a sufficient optical performance without surface cracks, cloudiness, scratches, and the like even when the glass material contains a highly reactive component. Also disclosed are an optical element having a sufficient optical performance without surface cracks, cloudiness, scratches, and the like and a method for manufacturing the same. Specifically disclosed is a glass material for press forming which comprises a core portion composed of multicomponent optical glass and a surface glass layer covering at least a region serving as an optical functional surface of the core portion. The surface glass layer contains more than 90 mass % of SiO2, and the thickness of the layer is less than five nanometers. Also specifically disclosed is a method for manufacturing a glass optical element by heating the glass material and by press forming the softened glass material using a forming die.