Cr 39 Lenses Vs Polycarbonate

With a higher Abbe value, Trivex exceeds in optical performance. I have several different pairs of plastic rim glasses and cr-39 fits fine in every of them. The lens are slightly thicker and heavier than poly, however, not by that much. After wearing cr-39 for a while now, poly carbonate looks really bad. It’s not just the sharpness of vision, but the poly seems like it really is uneven in strength in various elements of the lens. This can be a poor optics the nice doctor is talking about. It combines the positives of polycarbonate with higher optical quality, which makes it a step in the right direction for lens prescriptions.

• They’re moulded from liquid resin and properly cured over an interval of hours.
• Some even include polycarbonate single-vision lenses in the price, such as for example Warby Parker or Liingo Eyewear.
• GlassesUSA has a huge selection of contacts, glasses, & sunglasses.
• [newline]The refractive index of a simple plastic lens (CR-39) is 1.498 and therefore light travels 1.498 times faster in a vacuum than it can through the plastic lens.
• Consider the lenses used in expensive cameras and in telescopes.
• Today, there’s many different types of lens from which to choose.

Polycarbonate lenses are specially unique because they are used for more than lenses. Polycarbonates are also found in the manufacturing of electronic components such as DVD’s, CD’s and cell phone parts. What’s even more intriguing is how they’re found in space and aviation. That’s right, polycarbonates are employed for automotive and aircraft components aswell. They are applied to the Lockheed Martin F-22 canopy and also used as helmet visors for astronauts, and for bullet resistant glass and space shuttle windows. Furthermore, due to being extra thin, they’re ideal for thicker prescriptions.

Benefits Of Plastic Lenses

MR8 which is used for 1.67 buyingprice is $3.0 a peace. They call that SHMC (superhydrofobic, hardcoat, multicoat which is AR and UV-400). Progressive lenses CR39 are about $7.- a bit for induvidual.

However, even with the coating, plastics remain not 100% protected from scratches. CR-39 lenses have zero UV protection unless it really is added by soaking the lenses in a UV solution bath , which evaporates over an interval of 2 or 3 3 years. All other lens materials have full UV protection simply by the nature of the material and will not evaporate .

Polycarbonate: The Upgrade Lens

CR-39, or allyl diglycol carbonate , is really a plastic monomer commonly used in the manufacture of eyeglass lenses alongside the other material PMMA . CR-39 plastic comes with an index of refraction of just one 1.498 and an Abbe number of 58. Trivex was introduced to the optical market in 2001 and contains gained much popularity. Much like polycarbonate, Trivex has superior impact resistance, is thinner and lightweight, and has 100% UV protection. High index is the thinnest eyeglass lens available, not only is it lightweight. Because these lenses tend to reflect more light, most opticians and eye doctors recommend adding an anti-reflective coating to lessen glare.
Glass lenses are effective at improving vision, but they’re heavy and an easy task to break. Today, technology has improved and given us many more options, so glass is not any longer trusted for lenses.
They are able to still break, therefore official safety glasses ought to be worn for eye-hazardous jobs and sports. Additionally, Trivex and polycarbonate naturally block most UV light and do not need the use of a UV coating. Also, they are lab favorites for use in rimless frames, because polycarbonate lenses could be easily drilled and resist cracking around the drill holes. A disadvantage of polycarbonate is that it’s naturally a soft material causing it to scratch much easier. However, unlike CR-39 basic plastic lenses, a scratch resistant coating is nearly always standard since it is applied when the lenses are made. With higher refractive indexes, there are often more chromatic aberrations, meaning visual disturbances of light, that could be interpreted as blur by some. Chromatic aberrations are higher in polycarbonate lenses.

Trivex material provides the optical quality that optimizes corrective prescriptions and helps to reduce eye strain. I have -3.50 in both eyes and also have always worn glasses with polycarbonate lens.

But, I have four glasses all with the same script, one aspheric polycarbonate, one polycarbonate and one CR-39. The CR-39 is a lot sharper and clearer than the other two. It’s obvious to my eyes that CR-39 is really a huge improvement looking out of them in virtually any direction include center. The greedy lens sales representatives always push the more expensive poly or high index. The greater the power of lens, the more it really is affected by chromatic aberration. This means that you must never never get poly or high index for those who have a strong prescription. You can buy an excellent poly lens, but it will definitely cost 10x to 40x up to the equivalent within an inexpensive CR-39.