BS EN ISO 7944:1998

This standard BS EN ISO 7944:1998 Optics and optical instruments. Reference wavelengths is classified in these ICS categories:

• 11.040.70 Ophthalmic equipment
• 17.180.01 Optics and optical measurements in general

This International Standard specifies two reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, as well as ophthalmic lenses. It defines the associated principal refractive indices and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions.