UV rays or Blue light?
How to choose the right lens?
Vision needs change over time. T
Let's take a look.
Sunlight is made up of radiation at different frequencies, which includes: ultraviolet (UV) radiation, infrared (IR) radiation, and the visible spectrum (wavelengths from 390 to 760 nm), only a minimal portion of which is visible to the human eye.
As we can see in this image, ultraviolet (UV) light has wavelengths of less than 390 nanometers. This light is filtered and doesn’t reach the retina, but it can be absorbed by the cornea, the conjunctiva, and the crystalline lens and has the potential to cause permanent damage.
Ultraviolet (UV) radiation is in the invisible portion of the electromagnetic spectrum, from 100 to 400 nm, and can be divided into three ranges (i.e. UVA, UVB and UVC) based on their biologicaleffects.
- UV-C rays are 100% absorbed by Earth’s electromagnetic field.
- UV-B rays are 95% absorbed by Earth’s electromagnetic field and ozone layer.
- All of the UV-A radiation reaches the eye. The damage caused by UV-A radiation is cumulative and permanent and can affect the cornea, the crystalline lens, the iris, the retina, and relatedconjunctival and epithelial tissue:
- Dry eye and oxidative reactions of the conjunctiva
- Yellowing and loss of transparency of the crystalline lens
- Damage to the cornea
This is why, just as we should protect our skin with sunscreen even on a cloudy day, it’s a good idea to use lens filters that protect our eyes from 100% of the potentially harmful UV rays, such as our NoUV 400 lenses.
Divel Italia NoUV 400 lenses are the right choice for anyone who:
• Spends a lot of time outdoors
• Needs strong corrective lenses (NoUV is available in all indexes, from 1.50 to 1.74)
• Want colored lenses for their prescription eyewear (our 1.50 index lenses are ideal for tinting)
UV protection can be added to lenses by way of various coatings (such as our Performance NoUV). The difference lies in the fact that a NoUV lens is made with a material that absorbs UV radiation on its own. Filter coatings are applied to the outside of a lens, so care needs to be taken in order to keep the filter in good condition.
Now let’s talk about blue light. When do you need lenses that block blue light?
Visible blue light falls in the 400 to 500 nm range of the visible spectrum. The “low” end of the visible spectrum, particularly blue light in the 400-450 nm range, is known as high-energy visible (HEV) light and can be as harmful to our eyes as UV rays. Because it possesses a greater quantity of energy than light at other wavelengths, HEV light can damage the structure of the eye when it hits the retina.
Our Blue Natural lenses block all light up to 420 nm, i.e. both UV radiation and high-energy blue light, while letting through the blue light we need to see colors normally.
As you will probably be aware, electronic devices such as computers, phones and tablets are sources of blue light.
Using eyewear that blocks blue light, like Divel Italia’s Blue Natural, is indispensable for anyone who:
- Spends a lot of time looking at screens (of computers, tablets, phones, TVs, etc.)
- Spends a lot of time outdoors
- Doesn’t have a particular need for corrective lenses but wants protection when using a computer (Blue Natural is also available as a neutral filter)
So how do you pick between a NoUV or Blue Natural lens?
It’s easy. Blue Natural protects against both UV rays and blue light, whereas NoUV alone is not enough if you spend a lot of time at a computer.
Blue Natural is right for:
- People who work in an office or in front of screens, such as engineers, bank workers, doctors, graphic designers, photographers, lawyers, social media influencers, and anyone who spends a lot of time using a computer or playing video games.
NoUV is right for:
- People who work outdoors or in open spaces, such as restaurant staff, construction workers, landscapers, architects, drivers, fuel-service workers, waste-management workers, postal workers, and anyone who loves outdoor activities like running, cycling, or hiking.