When you want to equip your pair of sports glasses with your prescription, it is better to think twice about the tint of the lenses you are going to order. To do this, you need to ask yourself a few practical questions that will help you make the right choice:

- What is my main use for this pair of glasses?

- What time of the year do I use them?

The choice of your lenses naturally follows from these 2 questions. Indeed, defining the main choice is THE major QUESTION. We all have multiple sporting activities during which we want to use our sports glasses, but of course, we have to make compromises: Whatever your choice, your lenses will not perform well in all situations, so it is important to know the main use.

Let's add to the equation the time of the year during which we practice our main activity: Is it rather summer when the days are very long and the weather rather sunny or all year round in all seasons, including winter when evening falls at 4:30 p.m.…? To meet all the needs of athletes, a type of lens has established itself in the sports eyewear landscape in recent years: PHOTOCHROMIC 0-3 lenses!

What are 0-3 photochromic lenses?

As their name suggests it, these are lenses that darken with light, or more precisely with the amount of UV rays received. These glasses are coated with pigments containing photo-sensitive molecules which are activated by UV and whose physico-chemical reaction is reversible. The greater the quantity of UV, the more the chemical reaction occurs. As soon as the quantity of UV is reduced, the number of colored molecules decreases, thus lightening the glass until it becomes perfectly transparent at nightfall. The term 0-3 indicates the categories of lenses in the deactivated state (Category 0, i.e. transparent without tint) in the activated state (Category 3, the standard category of sunglasses).

As you will have understood, photochromic lenses are the most versatile lenses that can be found, including for indoor or night sports (long-distance cycling, for example).

So does the perfect glass exist? Not quite !

Photochromic lenses will cover 90% of your needs but there will be times when these lenses reach their limits:

- - Glasses sensitive to temperatures: Unfortunately yes, the photo-chemical reaction is slowed down and limited by rising temperatures; In other words, the hotter it is, the less well they work; In the middle of a heatwave at 40°C in the sun, your lenses will painfully reach category 2 while in the mountains at 0°C, the lenses will easily reach category 3, or even flirt with category 4!

- Lenses that do not darken in the car: It's quite simple, the windshield of our cars filters almost all UV rays, so the lenses cannot darken due to lack of UV rays... A good reason to switch to a convertible car!!! At METAOPTICS, we have opted for the best. This is the latest generation TRANSITIONS 8 technology. The lenses activate and deactivate quickly and the operating dynamics are very durable (4 to 5 years with the same performance). They reach 80% of their maximum shade in 30 seconds.

You can even opt for adding a mirror effect which will slightly darken your lenses by 2 to 3% but which will allow you to match your glasses to your sports outfit!