Tinted glasses are eyeglasses lenses tinted by applying absorbent coatings through the process of vacuum deposition. These thin coatings consist of metal or metal oxide mixtures and can be vacuum deposited only at certain high temperatures. They also have a high refractive index, meaning that they increase reflectance. They are deposited in multiple layers so that the properties of the glass remain intact. Due to the tinting of the metal or metal oxide mixtures, these lenses are available only in brown shades of different levels of absorption. Almost all plastic lenses are tinted in a special dye bath. To do this, several lenses are mounted on special holders and then immersed in the bath. While the eyeglass lenses are in the immersion bath, the dye particles penetrate to about 0.1 millimeter beneath the surface of the lens and become firmly embedded in it. Each immersion basin is equipped with a magnetic agitator to ensure that all eyeglass lenses are tinted evenly. The dye substances used also have applications in the textile industry. It is possible to match every color sample provided, tinting plastic lenses in any conceivable color and light reduction level based on the primary colors of red, yellow, and blue. Lenses with gradient colors can also be produced with special equipment, allowing for a gradual tint transition from light to dark by subjecting the eyeglass lenses to a predetermined exchange speed. This means that it is not only possible to pick out eyeglass frames, but also the tint of the lenses, resulting in eyeglasses with a personalized optical design, even if this means that not all colors can be perceived in their original shade.
Each color of lens is suited for specific situations. You will notice that many of the color properties overlap with each other. Whether they are performance, therapeutic, or fashion tints, each color causes the patient to perceive their surroundings differently. The most common tinted lens color is grey. At its darkest it can hide a poker face, help a deep sea fisherman snag the catch, and improve visual performance when driving. Grey lenses are color neutral, which means that they do not distort the integrity of colors, keeping them true. In fact, grey lenses have been in use by the U.S. Military for over 45 years because of their superior performance in various lighting conditions.
Some people prefer a grey/green lens to the traditional brown, citing that it provides crisper contrast, while being more color neutral than brown.
Brown/Amber lenses are also a popular choice. They provide better contrast and depth perception than grey, but colors are distorted. Brown/amber lenses are great for bright light conditions, but are especially suited to overcast, hazy, or foggy conditions. They block out blue wavelengths, which highlights the differences in greens, which can be helpful for golfers and baseball players.
Individuals who do a lot of driving would benefit from yellow lenses. The added contrast will decrease fatigue and increase visual acuity when driving in fog or haze, in overcast conditions, and at evening/night. For these same reasons, bikers, pilots, tennis players, hunters, and sport shooters can benefit from this lens.
Orange lenses eliminate blue light. They are perfect for sports that require an object to be tracked against the blue sky, such as a baseball. These lenses are often the lens of choice for clay target shooting on a cloudy day, but can also be helpful to bikers, skiers, and hunters.
Vermilion is a reddish/orange lens often used by individuals who like to hunt and fish. It is chosen for its contrast capabilities. There are patients who are more satisfied with this color than with the more common brown and grey.
Red is a robust color that provides contrast and is another variety best suited for specific purposes. Clay target shooters may use this color in extremely sunny conditions. Fishing enthusiasts may opt for this lens when fishing in the early morning or later evening.
Violet deserves mention as more than a fashion tint. Sport shooters and other athletes will use it for contrast in mid to bright conditions. Fashion tints are generally tints applied for the appearance of their color rather than any traits of that color. Common examples of fashion tints are green, blue, pink, and purple.
Tints of any purpose can be applied as a solid tint, causing the lens to be one solid, uniform color, or a gradient tint, when the intensity of the color lightens as it approaches the bottom of the lens. Double gradients and other color designs can be applied. For rimless or semi-rimless frame styles, edge tinting is also an option.