Transition glasses: What are they and how do they work?
Transitions are called those glasses that change the color of their lenses, adapting to the lighting conditions: in the bright sun, the glasses darken, but remain transparent indoors.
Photochromic lenses serve for these changes. They react to the ultraviolet light, which ensures that the glasses do not darken indoors. When ultraviolet rays hit the lenses, the photochromic particles react resulting in reduced light transmission. The degree of darkening of the lenses can reach 85%.
Temperature conditions also matter: in hot weather, photochromic glasses cannot darken to their maximum value, whereas at medium and cool temperatures, the speed and degree of darkening is higher. Therefore, for a vacation in hot countries, it is better to buy sunglasses with diopters, but in urban conditions blue light transition glasses will protect your eyes from bright light. You should remember that transition glasses react to ultraviolet light, so they can change color even in cloudy weather.
Glasses with photochromic lenses combine the benefits of corrective and sun-protective glasses. That’s very convenient for people with poor eyesight who cannot provide protection to their eyes on a sunny day, because they have to wear corrective glasses. Photochromic lenses are also recommended for people with photophobia or those who suffer from eye diseases.
Who needs blue light transition glasses?
To begin with, in photochromic glasses anti-blue lenses are used that filter out harmful HEV light (blue light), which emits every light source. Unfortunately, this harmful light is contained in especially high concentration in the devices that we use everyday – phones, computers, tablets, TV. Pernicious influence of the blue light causes frequent headaches, fatigue and dry eyes, blurred vision, eye strain, visual fatigue and sleep disorders. You can easily avoid all these hurtful symptoms and choose your perfect blue light photochromic glasses that will help you to cope with all the negative symptoms, effectively reducing eye strain and improving night sleep.
How to choose photochromic glasses?
First of all, choosing transition glasses it’s better to pay attention to:
1. Lens material
Transition lenses can be both made of glass which are called mineral lenses, and of plastic, they are also called polymers. Both of them have certain pros and cons, so it is impossible to say that one option is definitely better than the other.
For example, plastic lenses provide a higher level of dimming – up to 85%. The molecules of photochromic substances are more active in them, so the rate of darkening of such glasses may be slightly higher than that of glass ones. And the most important is that it is the best choice for people who lead an active lifestyle: polymer lenses are less traumatic for the eyes in case of damage. At the same time, plastic lenses are more easy to scratch, which may slightly worsen their photochromic characteristics. They are less resistant to external influences, and therefore less reliable.
In turn, glass lenses cope with any level of poor eyesight and better resist abrasive effects. However, in mineral lenses the photochromic characteristics are usually slightly lower: the maximum degree of darkening is less than 70%, the speed at which the lenses change color is inferior than in the plastic ones.
2. Darkening color
As a rule, photochromic lenses change their color to the most popular and convenient colors used in sunglasses – brown, gray or green. These colors are the most comfortable for the eyes and provide the most natural environment for eyes.
Some manufacturers offer a wider palette for photochromic glasses, for example, sapphire and amethyst colors of photochromic lenses.
3. The speed of change of the color
In general, the speed at which the lens changes its transparent color to the darkest possible and lightens back is from 30 seconds to 5 minutes. As a rule, the lenses of the premium segment darken faster than more budget glasses.
4. Protective coatings
Additional coatings can help you to protect the lenses from external influences and create more comfortable conditions for using glasses, which will perfectly fit you. For example, lenses with a water-repellent coating rain can be used even in rain – drops quickly roll off the glasses, leaving no wet traces.
5. Life cycle
Unfortunately, even high-quality photochromic glasses sooner or later lose their characteristics. Transition glasses are recommended to be changed once every three years. During this time, both photochromic and protective functions deteriorate, so it is important to update your glasses in time.
Pros and cons of photochromic lenses
Let’s start with the advantages of the transition glasses:
- “Two in one” – glasses with photochromic lenses significantly facilitate the life of people who need vision correction. You no longer need to choose between the good eyesight and opportunity to stop screwing up, photochromic glasses will provide both correction and protection from bright sunlight;
- Option for the people with eye diseases and photosensitivity. The glasses, which quickly adapt to changes in lighting, effectively protect the eyes from pain and discomfort, caused by increased sensitivity to light;
- These special glasses also can be used by the drivers because the glasses with such lenses react not only to ultraviolet radiation, but also to visible light, so that the lenses darken, even if they are not directly exposed to the sun.
The disadvantages of the transition glasses:
- Photochromic blue light glasses often are more expensive than usual corrective or sun-protective glasses. However, the shops offer a wide variety of glasses with different price, which allows you to choose photochromic glasses for almost any budget;
- A limited range of colors – unlike sunscreen and tinted optics, photochromic glasses have a smaller palette of possible darkening colors.
Let’s summarizePhotochromic glasses are a salvation for people who need vision correction. Glasses with such lenses remain light in the room and darken under the influence of sunlight. Transition glasses are also recommended for people who suffer from eye diseases that provoke photophobia.