ISO/TR 20772:2018 PDF

Overview

ISO/TR 20772:2018 - Ophthalmic optics - Spectacle lenses - Short wavelength visible solar radiation and the eye - is a technical report that explains how short‑wavelength visible solar radiation (380–500 nm) is transmitted to and within the human eye and what effects these “blue wavelengths” can have. The report clarifies the science behind blue‑light and near‑UV transmission, describes the filtering effects and measurement of spectacle lenses and sunglasses, and provides background needed to interpret transmittance requirements in existing spectacle‑lens and sunglass standards. It does not cover protection from artificial light sources.

Key topics

• Wavelength range: Focus on 380 nm to 500 nm (violet, indigo, blue) and the choice of 380 nm as the UV/visible boundary in ophthalmic standards.
• Solar radiation & geometry: How atmospheric, geometrical and reflective factors affect eye exposure and retinal irradiance.
• Physiological effects: Discussion of ocular hazards, retinal blue phototoxicity, special considerations for children’s eyes, peripheral focusing effects and non‑visual (circadian) impacts of blue light.
• Spectral weighting & limits: Use of spectral weighting functions (including reference to ICNIRP 2013) for assessing photobiological risk and application to spectacle/sunglass standards.
• Filtering materials & measurement: Materials and treatments affecting transmission, reflection and absorption; principles and accuracy factors for measuring spectral transmittance of lenses and filters.
• Standardization context: Background on terms like UV400 and alpha‑blocking wavelength and how these claims are defined and verified in standards.

Applications

ISO/TR 20772:2018 is a practical reference to:

• Interpret and verify marketing claims such as UV400 or “blue‑blocking”
• Guide selection and specification of coatings, tints and filter materials for spectacle lenses and sunglasses
• Inform test methods and laboratory measurement procedures for spectral transmittance
• Support product design decisions that balance visual performance and photobiological protection
• Provide scientific background for risk assessments related to solar blue‑light exposure

Who should use it

• Spectacle and sunglass manufacturers and designers
• Standards developers and conformity assessment bodies
• Optical testing laboratories and calibration services
• Ophthalmic clinicians, ocular safety researchers and public health regulators
• Product compliance and labeling teams

Related standards and references

• ISO 8980‑3 (tinted spectacle lens technical requirements)
• ISO 12312‑1 (sunglasses - general requirements)
• ISO 13666 and ISO 4007 (vocabulary for ophthalmic optics and eye/face protection)
• ICNIRP publications referenced for spectral weighting

The Technical Report also includes a bibliography of scientific sources useful for further reading on blue‑light transmittance, retinal effects and measurement methods.