UVA: Seeing and not tanning.
Ultraviolet (UV) radiation is a form of electromagnetic energy emitted by the sun and artificial sources like welding machines, tanning beds, and UV lamps. UV radiation is divided into three primary types based on its wavelength: UVA, UVB, and UVC. Each type has different characteristics and effects on the eye:
UVA (Ultraviolet A)
Wavelength: 315-400 nanometers (nm).
Characteristics: UVA rays are the longest wavelengths of UV radiation and are not as energetic as UVB and UVC rays. They can penetrate deep into the skin and eyes.
Effects on the Eye:
UVA rays can pass through the cornea and reach the lens and retina inside the eye.
Long-term exposure to UVA can cause significant damage to the retina, potentially leading to conditions like macular degeneration, which is a major cause of vision loss in older adults.
UVB (Ultraviolet B)
Wavelength: 280-315 nm.
Characteristics: UVB rays have shorter wavelengths than UVA and are more energetic. They are mostly absorbed by the ozone layer, but a significant amount still reaches the Earth's surface.
Effects on the Eye:
UVB radiation is mostly absorbed by the cornea.
Exposure to UVB rays can cause photokeratitis (similar to a sunburn of the eye's surface), which is painful and can cause temporary vision loss.
Chronic UVB exposure contributes to the development of cataracts and pterygium (a benign growth on the surface of the eye).
UVC (Ultraviolet C)
Wavelength: 100-280 nm.
Characteristics: UVC rays are the shortest and most energetic of the UV spectrum. Fortunately, nearly all UVC radiation is absorbed by the Earth's ozone layer and does not reach the ground.
Effects on the Eye:
Under normal environmental conditions, UVC does not pose a risk to the eyes because it is absorbed by the ozone layer.
However, exposure to UVC rays from artificial sources can be extremely harmful, causing severe burns to the cornea and even permanent damage if exposure is intense enough.
Protective Measures
Due to these harmful effects, it's crucial to protect the eyes from UV rays. This can be effectively done through:
Wearing sunglasses that block 99 to 100% of both UVA and UVB rays.
Using hats with brims to block UV rays from reaching the eyes.
Avoiding direct sun exposure during peak UV hours, typically from 10 a.m. to 4 p.m.
Understanding these different types of UV radiation and their specific impacts on the eye helps in adopting the right protective measures to prevent long-term damage and maintain eye health.
Sunmax Optical provides specialized UV protective lenses that block 20% and more. Please kindly email us for more information
