Myth Busting for the UK. [Archive] - OptiBoard Discussion Forums

labtech

06-13-2006, 06:59 AM

Hi,
I wonder if you could possibly help in challenging some of the myths that I have come up against regarding Transition lenses.

Do they / Should they be used whilst driving
Does a car windscreen alter the behaviour of the lens, i.e. heated/re-radiating screens
What are the upper and lower ambient temperatures that allow the lens to work to its best, i.e. can they be worn in Iceland and Saudi Arabia.
What are the effects of applying and AR coat.
Can I pre tint the lens in order to make it darker when worn indoors, silly question I know , but one which I have been asked.
I hope you can answer the above above questions and tahnk you for your time.

Labtech UK

Jim Schafer

06-18-2006, 08:27 PM

Hi Labtech,

I have been out of the office since the 9th and did not get a chance to stay up with the board.

Ok..to help with your myths/urban legends...

1. You can wear Transitions where ever you would a clear lens. Yes, you can wear them while driving.
2. Yes, the windscreen does affect the performance of plastic photochromic lenses. It is the uv blocking properties of the glass that will not allow full reaction of the photochromics to take place. Before you ask, a mineral photochromic lens will darken in a car because they darken with uv and visible light. No clear to dark photochromic lens regardless of material will darken enough to be a good driving lens (for long periods of driving, not short jaunts). Driving and fishing is why God invented polarized lenses.
3. Yes, you can and many people do wear Transitions lenses in Iceland and Saudi Arabia. Transitions are meant to be a comfort lens, good for everyday needs. For ultimate comfort during extended times outdoors in the mentioned countries and nearly anywhere else on earth, a good quality polarized sun lens is recomended. BTW...23°c/72°F is perfect performance temp for photochromic lenses..
4. Transitions and AR are the perfect pair. Since the mid 1990's all Transitions products were developed with AR in mind. AR will raise the indoor transmission by 3 to 5 points and has little or no effect on full darkening performance.
5. Tinting a Transitions will only affect the indoor transmission.
Keep in mind semi finished Transitions lenses have non tintable hardcoats on the front surface and stock FSV are totally non tintable (hardcoated on both sides)

I hope this helps,
Jim