UV rays or Blue light?

The material selected for a lens is fundamental, as it determines both comfort and clarity of vision.

How to choose the right lens?

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.