How are the lenses for your glasses made?

At Divel Italia, we have recently installed new equipment at our Milan production lab to further strengthen our production of prescription lenses.

But what are the steps involved in making a prescription lens?

How are the lens­es for your glass­es made?

But what are the steps in­volved in mak­ing a pre­scrip­tion lens?

From the de­sign and de­vel­op­ment of our first free-form, pro­gres­sive lens, Au­ro­ra Clear by Di­v­el Italia, our Mi­lan lab has con­tin­ued to evolve and bring in the most so­phis­ti­cat­ed equip­ment avail­able. Along­side these equip­ment up­grades, our Re­search & De­vel­op­ment lab has been de­sign­ing the in­creas­ing­ly in­no­v­a­tive soft­ware that has en­abled us to cre­ate the lat­est ad­di­tion to the Di­v­el fam­i­ly: our pro­gres­sive lens ALIENA. ALIENA is an ex­treme­ly com­fort­able lens that elim­i­nates dis­tor­tion and en­sures strain-free vi­sion. But what are the steps in­volved in mak­ing a pre­scrip­tion lens?

1) BLOCK­ING The semi-fin­ished lens, known as a lens blank, is tak­en from our in­ven­to­ry. Blanks can be made of ei­ther plas­tic (which is the most com­mon) or min­er­al (e.g. glass). The blank is “semi-fin­ished” in that the out­er side is al­ready curved. It is on the in­ner side that the ma­chin­ery will act in or­der to cre­ate the right pre­scrip­tion for the fin­ished lens. The first step in mak­ing the lens is called BLOCK­ING. The lens blank, with its pro­tec­tive film, is placed in a spe­cial ma­chine that af­fix­es the blank to the sup­port that will en­able to lens to be held in place by the lens gen­er­a­tor. For Di­v­el’s first line, a large part of this block­ing was done man­u­al­ly. Now, it has be­come a semi-au­to­mat­ed process, and the block­ing of a lens blank takes just a few sec­onds.

2) GEN­ER­A­TION Lens GEN­ER­A­TION is one of the most im­por­tant steps in mak­ing a lens. This is the phase in which the lens is giv­en the thick­ness need­ed to re­pro­duce the rec­om­mend­ed pre­scrip­tion. The lens gen­er­a­tor is giv­en spe­cial soft­ware in or­der to cre­ate the lens de­sign. Each pro­gram is de­signed and de­vel­oped in our Mi­lan labs, and every year we re­lease bet­ter and bet­ter soft­ware that en­ables us to pro­duce lens­es that en­sure vi­su­al com­fort and min­i­mize any ar­eas of aber­ra­tion. Our new equip­ment has made the process even faster, so we are now able to gen­er­ate a lens in just one minute.

3) POL­ISH­ING The third step is lens POL­ISH­ING. Dur­ing this phase, the new lens is pol­ished so that it achieves an op­ti­mal de­gree of trans­paren­cy. The pol­ish­ing process is also cru­cial to en­sur­ing that the sub­se­quent coat­ings ad­here prop­er­ly to the lens.

4) BLOCK RE­MOVAL The lens is placed in a ma­chine that re­moves the block ap­plied pre­vi­ous­ly. Dur­ing this phase, the lens is rinsed with wa­ter and cleansers in or­der to elim­i­nate all dirt and grime and get the lens ready for its coat­ings.

5) HARD COAT­ING The pri­ma­ry treat­ment done to a lens is the hard coat­ing, which helps to hard­en the lens and make it more durable and scratch re­sis­tant. A spe­cial hard­en­ing lay­er is ap­plied to both sides of the lens to pro­tect the lens against scratch­ing and or­di­nary wear and tear. This hard coat­ing is ap­plied by dip­ping the lens in a vat of spe­cial hard­en­ing enam­els of dif­fer­ent re­frac­tive in­dex­es. Al­ter­na­tive­ly, these enam­els may be ap­plied by way of spin­ning.

6) AR Lens coat­ings are es­sen­tial in or­der to give the lens a va­ri­ety of char­ac­ter­is­tics in ad­di­tion to the pro­tec­tive hard coat­ing, in­clud­ing:

  • Anti-re­flec­tion
  • Dust re­pel­lent
  • Wa­ter and grime re­pel­lent

Dur­ing this high-vac­u­um AR phase, a batch of lens­es is placed in a cham­ber and loaded into a spe­cial ma­chine in which the var­i­ous crys­tals of the coat­ing to be ap­plied are va­por­ized. It is dur­ing this phase that we cre­ate coat­ings such as Di­v­el Italia’s PER­FOR­MANCE or our brand-new PER­FOR­MANCE PLUS, which gives the lens an ad­di­tion­al oil-re­pel­lent lay­er for en­hanced re­sis­tance to liq­uids, dirt and grime.

** 7) MARK­ING** Dur­ing the MARK­ING phase, the lens­es are giv­en the mark­ings need­ed in or­der for the op­ti­cian to cen­ter the lens­es in their frames, so as to op­ti­mize the per­for­mance of the var­i­ous lens zones. The lens­es then go to qual­i­ty con­trol

8) QUAL­I­TY CON­TROL The next-to-last step is qual­i­ty con­trol. Dur­ing this phase, a spe­cif­ic ma­chine is used to en­sure the lens has the prop­er cor­rec­tive pow­er and to check for any scratch­es and/or im­prop­er­ly ap­plied coat­ings. When a lens pass­es this QUAL­I­TY CON­TROL, it is ready to be sent to the op­ti­cian.

9) PACK­AG­ING Af­ter plac­ing the lens­es in their pack­ag­ing along with their war­ran­ty card, they are shipped ei­ther to a Di­v­el branch of­fice or di­rect­ly to the cus­tomer. At our Di­v­el lab, we also pro­duce pre­scrip­tion sun­glass lens­es, such as our FO­TOCHRO­MA, SPEEDY, FO­TO­COL­OR and po­lar­ized lens­es, which can be made in ei­ther mono­fo­cal or pro­gres­sive ver­sions.