Abstract: The purpose of the present invention is to provide a myopia prevention device. A myopia prevention device of the present invention comprises a light transmission part selected from a group consisting of an eyesight correcting tool, an eye protection tool, a face protection tool, a sunshade, a display device, a window, a wall, a light source covering, and a coating material. The light transmission part of the device transmits light having a wavelength within a range of 350 nm to 400 nm inclusive and thus suppresses the occurrence and progression of myopia. Further, a myopia prevention device comprises a light emission part selected from a group consisting of lighting equipment, a display device, and a light irradiation device. The light emission part of the device emits light having a wavelength within a range of 350 nm to 400 nm inclusive and thus suppresses the occurrence and progression of myopia.

Abstract: A wavelength-selective transmissive glass has a light transmittance Tmore than 315 nm and 400 nm or less at a wavelength of more than 315 nm and 400 nm or less represented by the formula shown below of 1% or more in terms of a plate thickness of 6 mm and a light transmittance T315 nm or less at a wavelength of 315 nm or less represented by the formula shown below of 60% or less in terms of a plate thickness of 6 mm. Ak is a weighting factor at a wavelength k (nm) for calculating T (light transmittance) defined in ISO-9050:2003, and Tk is a transmittance at the wavelength k (nm) in terms of a plate thickness of 6 mm: Tmore than 315 nm and 400 nm or less=(?k=more than 315400 Ak×Tk)/(?k=more than 315400 Ak) T315 nm or less=(?k=300315 Ak×Tk)/(?k=300315 Ak).

Abstract: To provide an irradiation device capable of preventing myopia or slowing the progression of myopia by the action of light irradiated toward the eyeball. An irradiation device (10) comprises a light source (1) and an instrument (2) on which the light source (1) is mounted. The light source (1) emits at least light having a wavelength within a range of 350 to 400 nm, inclusive, and is disposed in a position that allows irradiation in an eyeball direction when the instrument (2) is mounted. Further, the light source (1) is disposed in a position 0 to 100 mm, inclusive, from a surface of the eyeball. At this time, an irradiance of the light having a wavelength within the range of 350 to 400 nm, inclusive, is 0.02 to 1.0 W/m2, inclusive, on the eyeball surface when the instrument (2) is worn.

Abstract: A wavelength-selective transmissive glass article has light transmittance Tmore than 315 nm and 400 nm or less at a wavelength of more than 315 nm and 400 nm or less of 1% or more. In addition, the wavelength-selective transmissive glass article has light transmittance T315 nm or less at a wavelength of 315 nm or less of 60% or less.