just share some information here ,
how do prove that is a transition lens
1.certificate of authenticity card
2.lens packaging (verify ur power is the same on the packaging,this is very important) .

diff brand ,diff price
1.essilor ,hoya, carl zeiss (very good quality)
2.BBGR +SC coating(very small diff as above)
3.ILT + steel coating(a bit lower grade than 2 above)
4.others ( not worth to try)

hope u guys can enjoy UR transition lenses

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Added on April 7, 2011, 11:52 pmthere r 2 type of changing color lenses on the market
1.Transition
2.Photochromic(sunactive,magic sun visor n...................so many brand)

Transition
1.more expensive
2.change color darker n faster
3.darkest abt 75 or 76 % at 35°C
4.quality assured , lifespan abt 3years

Photochromic
1.budget ,cheaper.
2.color not so dark n fast
3.easy become yellowish
4.change color slower after some time.

both of them wont change darker in the car.

So where`s ur fren store located?name?