Photochromic how does it work

Often referred to as transitions or reactolights, p hotochromic lenses are made of many lens materials including plastic, glass or polycarbonate. They are typically used as sunglasses that conveniently switch from a clear lens indoors to a sunglasses depth tint when outdoors, and vice versa. They typically take around 30 seconds to fully darken and between two to five minutes to return to a clear state.

Photochromic lenses were created in the s at the Corning Glass Works Inc. They will return to an almost clear state within two minutes and be fully clear within five minutes, however, excessively high or low temperatures can affect this timeframe.

Photochromic lenses are an extremely convenient, cost effective and beneficial purchase for a number of reasons, although, there are some weaknesses. There are pros and cons of photochromic lenses and sunglasses, including those listed below:.

Reaction Times — Although photo lenses reaction from clear to sunglasses is quite quick, typically within 30 — 60 secs, the reversal takes a little longer as much as 5 minutes depending upon the temperature of the lens which could be dangerous if entering a dark room or certainly inconvenient at best.

Photochromic Lens Temperature Dependency:. Cold weather also increases the time taken to return to a clear shade. Plastic photochromic lens molecules of silver and halide are usually layered or embedded evenly onto the surface of the lens providing an even shade of tint when darkening. Glass photochromic lenses have the molecules contained within the glass and this can sometimes cause an uneven tinting effect on a lens with higher prescription due to the different thickness of the lens from one edge to the other.

Can I use Photochromic sunglasses for driving? Standard photochromic lenses do not work inside a car due to the windscreen blocking out the UV rays which are needed to active the chemical process which causes the lens to darken. However, individual photochromic lenses lifespans vary based on manufacturer, how often you wear them and how you use them.

When your photochromic lenses start to take longer and longer to transition from indoor to outdoor light, that's a sure sign it is time to get new transition lenses.

Ask your eye doctor if photochromic lenses are right for you or add them to your glasses order online. Home Sunglasses Sunglasses Types. By Adam Debrowski. Schedule an exam Find Eye Doctor. Your life and eyes 4 min read. Lens coatings, also known as lens enhancements, are a great way to make your lenses even more effective, improving your visual comfort and acuity.

Acting as a fundamental part of your prescription lenses, lens coatings have some of the most up-to-date technology to ensure healthy vision.

Home Blog Your life and eyes How do Photochromic lenses work? What are photochromic lenses? Your life and eyes 1 min read Discover the Must-Have Photochromic Lenses for Summer If you're thinking of making the most of the summer this year, make sure you have the right protection for your eyes with photochromic lenses. Your life and eyes 3 min read How do polarised lenses work? Your life and eyes 4 min read Improving your visual comfort with lens coatings Lens coatings, also known as lens enhancements, are a great way to make your lenses even more effective, improving your visual comfort and acuity.

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