Contribution to the radiation protection for sunglasses standards

Area of Science:

• Ophthalmology
• Photobiology
• Environmental Health

Background:

• Established safe limits for eye exposure to ultraviolet (UV) radiation (180-400 nm) consider spectrally weighted and total radiant exposure.
• Current sunglasses standards primarily focus on UV protection within the 280-380 nm range to meet spectrally weighted exposure limits.

Purpose of the Study:

• To evaluate the adequacy of existing UV protection standards for sunglasses in Brazil.
• To assess the impact of extending the upper UVA limit to 400 nm based on Brazilian sunlight irradiance.

Main Methods:

• Calculated UV exposure limits for 27 Brazilian state capitals.
• Analyzed the difference in ultraviolet radiant exposure between the 280-380 nm and 280-400 nm spectral ranges.

Main Results:

• The 2013 review of the Brazilian standard incorporated an upper UVA limit of 400 nm.
• High sunlight irradiance in Brazil results in a 49% greater average ultraviolet radiant exposure over 280-400 nm compared to 280-380 nm.

Conclusions:

• The findings suggest a need to revise current sunglasses standards.
• Extending UV protection to 400 nm is crucial for adequate eye safety in high irradiance environments like Brazil.