Abstract: An optical article includes: an optical base; and a layer that is provided on the optical base and contains SiO2 as a main component, the layer being a silicon-nitride-containing silicon oxide layer containing SisOtNu (s>0, T?0, u>0).

Abstract: A multilayer antireflection layer includes a high refractive index layer and a low refractive index layer that are laminated alternately, the high reflective index layer having a grain boundary, and particles forming the grain boundary having an average particle diameter of 30 nm or less.

Abstract: An optical article includes an anti-reflection layer on a substrate, wherein the anti-reflection layer is formed of nine layers obtained by alternately stacking low refractive index layers and high refractive index layers, the layer closest to the substrate among the high and low refractive index layers that form the anti-reflection layer is called a first layer and the numbers of the following layers are incremented by one so that the odd-numbered layers are low refractive index layers and the even-numbered layers are high refractive index layers, and at least one of the following equations is satisfied: 0.8?0??1?1.2?0??(1) 0.8?0??3?1.2?0??(2) where ?0 represents a design primary wavelength greater than or equal to 480 nm but smaller than or equal to 550 nm, and ?k represents the optical thickness of the corresponding one of the high and low refractive index layers (k represents the layer number).

Abstract: An optical article includes: an optical base; and a layer that is provided on the optical base and contains SiO2 as a main component, the layer being a silicon-nitride-containing silicon oxide layer containing SisOtNu (s>0, T?0, u>0).