Colour lenses
Sunglasses are available with lenses of various colors. The effects of those colors on how you see the world are of course different. There are colors that mainly have a functional reason and colors that are more aesthetically intended.
Important when choosing the color lens is where and how to use the glasses. Do not just choose a color that makes the world beautiful, but go out of the moment of use. Yellow or orange glasses are contrast enhancing, which gives more depth; ideal for use in snow on cloudy days or during mountain biking in a dark forest.
In the bright sun you can wear brown or green glasses, and for everyday use, gray is most suitable, because of the natural vision.
Functional lens colours
Grey
Gray glasses, above colored, have the advantage of giving little or no color change. Because of less light in less light, colors become less intense. That goes for all sunglasses.
Grey-green
These make the most of the colors that the human eye is most sensitive to. As a result, you can see quite clearly, while still retaining a lot of light. Colors remain more natural, though on the cool side.
Brown
Brown glasses mainly filter out the blue of the sky. That blue light can reflect on snow and wet surfaces, which makes the image quieter with brown glasses, with improved contrast.
The world as you normally see it looks a lot lik lighting with incandescent lamps, colors and feelings are a little warmer. The colors you see are no longer really natural.
Because you feel more awake from blue light, you can feel less alert with sunglasses with brown glasses. Blue light also plays a role in overcoming jet lag, so it would be less effective if you wear a sunglass with brown glasses.
Yellow/orange
These are not really meant for bright sunlight, because the glass leaves quite a lot of light. They are more meant to have a better contrast, by filtering out the blue of heaven. They are mainly used by people who are important for sports, such as sports and winter sports. They also give a better view of mist or fog.
Degree of protection against bright light
The color of the lenses says nothing about the amount of protection they offer against harmful effects of bright sunlight. As long as you do not look directly in the sun, only UV radiation is harmful. An UV filter can be quite clear, so darkness or color of a sunglass, in itself, says nothing.
Sunglasses are not meant to use to look in bright light of lights or the sun. Wrong light can cause permanent damage to the retina. Blue light is the most harmful, so if you want to use sunglasses for this purpose, one with brown glasses is safest.
Polarizing lenses
Polarizing lenses also contain a polarization filter in addition to a UV filter. This filter has the characteristic of retaining the glare of the sun on road, water or snowflakes. How this works? Sunlight reaches the earth in wave movements. The light is radiating all sides. When it touches the earth, the light is reflected in two directions, horizontally and vertically. Vertical light allows viewing contrasts and colors, while creating horizontal light shine and glare. Water and other non-metallic surfaces backlight sunlight mainly horizontally and cause such a concentrated beam of sparkling.
The function of a polarization filter is to block horizontal light. With polarizing sunglasses, you have significantly less trouble with the nuisance of water, sunshine on the road and glare in many other situations.
Fotochrome lenses
Fotochrome lenses color darker as more light comes on. Crystals in the lens respond to the amount of UV rays. The more ultraviolet light, the darker the lenses color. Removing the UV radiation, the lenses are lighter. For example, Fotochrome lenses are functional during mountain biking. For example, the eyes are not blinded by the sun as you cycle out the forest. The glasses work less well in the car, because the tinted windscreen already prevents some of the UV radiation.
Lens material
Sunglasses lenses are made of plastic or glass. Plastic is strongest, can be easily coated with (mirror) coatings, is relatively scratch resistant and very light; ideal for active carriers. Well-cured glass lenses are generally more durable and scratch resistant, but also more expensive, heavier and more vulnerable.
Coatings
If you want to use one pair of glasses in different weather conditions, choose lenses with a coating or mirror coating. This makes the product a little more expensive, but has the advantage that the glasses get a much wider range of use. A category 2 glasses with orange glasses, for example, works contrast-enhancing on a cloudy day and also protects the eyes when the sun breaks through a mirror coating.
Removable lenses
Some brands have models in their assortment where standard different lenses are supplied. You can also order additional lenses for many models, which allows the glasses to be used in more weather conditions.