photochromic lenses

[d_a_h_u_k]

Hello everyone,

I've lurked here on occasion and learned quite a bit from everyone, but now I've finally decided to post since I am in search of some free advice :)

I was wondering what features of a photochromic lens are most important to you? Do you value speed, overall intensity, or the ability to have a lens that works decently with an AR coat? I've noticed that many grey lenses on the market have a bit of a purple tint to them, do you mind this or does it go unnoticed for the most part?

Thanks for letting me pick your brains!

[Chris Ryser]

I've noticed that many grey lenses on the market have a bit of a purple tint to them, do you mind this or does it go unnoticed for the most part?

The purplish grey lenses are most probably regular tinted lenss. The dyes for the grey color have probably been made with red as a base color. When the color starts to fade the red becomed dominant and together with the blue in the mix starts showing as purplish.

All color mixes have been made with the basic three colors.............red..........blue...........yellow.

You actually can tint any color by using any one of the above colors as the workhorse, meaning the main color used.

We have found that using blue as the workhorse we get better colors, specially in the greys and blacks and they will never go purple, as the red is only used as an adjusting media. ( The only puzzling fact to new users is that the dye does not always look the color it is going to end up on the lens)

How to to a basic tinting.......................

1) Tint lens medium blue

2) Tint yellow over blue = lens turns green

3) Dip into red = lens will become a greenish grey (G15)

4) Continue dip in red = lens will become a neutral grey (black)

5) Continue dip in red = lens will become grey brown

6) Continue dip in red = lens will become neutral brown

7) Continue dip in red = lens will become reddish brown

All is actually a simple process and with a little expirience you can reach any color you want.

[Slug]

A product that would perform the same in all climate conditions in my oppinion would be huge. I can't count the number of phone calls and even returns that we get as a laboratory in July and August because the patients glasses aren't darkening as they previously did.

[Andrew Weiss]

Consistency no matter what the temperature.
Density of color when fully activated, clear when not.
Ability to work properly in an automobile.
Speed.

Maybe not what you wanted to hear, but if someone developed a lens which does all of the above, I think you'd have a real winner.

[DragonLensmanWV]

Consistency no matter what the temperature.
Density of color when fully activated, clear when not.
Ability to work properly in an automobile.
Speed.

Maybe not what you wanted to hear, but if someone developed a lens which does all of the above, I think you'd have a real winner.

I always thought that if they darkened in a car, it would be because they are responding to visible light. This can be a real problem in many circumstances.
Imagine...
you're settling in to read the latest Terry Brooks novel. You sit in your favorite chair, bring your reading lamp over, flick it one, and.....your lenses darken making your extra illumination worthless.

[cocoisland58]

Hello everyone,

I've lurked here on occasion and learned quite a bit from everyone, but now I've finally decided to post since I am in search of some free advice :)

I was wondering what features of a photochromic lens are most important to you? Do you value speed, overall intensity, or the ability to have a lens that works decently with an AR coat? I've noticed that many grey lenses on the market have a bit of a purple tint to them, do you mind this or does it go unnoticed for the most part?

Thanks for letting me pick your brains!

The only "purple" lens on the market is from a bad pot of dye or a faded lens. This is why I only sell polorized or photosensitives. The best thing about a photosensitive lens is convenience. The only reason I even own a pair is for vacations when I am in and out of stores a lot.

[d_a_h_u_k]

I always thought that if they darkened in a car, it would be because they are responding to visible light. This can be a real problem in many circumstances.
Imagine...
you're settling in to read the latest Terry Brooks novel. You sit in your favorite chair, bring your reading lamp over, flick it one, and.....your lenses darken making your extra illumination worthless.

Yeah, photochromic dyes are activated by UV. Since any modern windscreen filters out the UV you're going to have a problem getting them to activate. If a car truly does filter out 100% of the UV spectrum, then you're not going to have a photochromic lens that activates in the car.

There are ways to work around the heat problem though, in the next few years there will probably be some lenses out that will perform better in the heat.

[d_a_h_u_k]

The only "purple" lens on the market is from a bad pot of dye or a faded lens. This is why I only sell polorized or photosensitives. The best thing about a photosensitive lens is convenience. The only reason I even own a pair is for vacations when I am in and out of stores a lot.

I wasn't writing about a purple lens, but grey photochromic lenses that actually do have a tiny bit of purple to them. If you take them outside on a white sheet of paper and let them activate next to something that is grey, you will notice a purple tint on some of them.