Sunglasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened.
The American Optometric Association recommends sunglasses that block ultraviolet radiation (UV) whenever a person is in the sun to protect the eyes from UV and blue light, which can cause several serious eye problems. Its usage is mandatory immediately after some surgical procedures, such as LASIK, and recommended for a certain time period in dusty areas, when leaving the house and in front of a TV screen or computer monitor after LASEK. It is important to note that dark glasses that do not block UV radiation can be more damaging to the eyes than not wearing eye protection at all, since they tend to open the pupil and allow more UV rays into the eye. Sunglasses have long been associated with celebrities and film actors primarily from a desire to mask their identity. Since the 1940s, sunglasses have been popular as a fashion accessory, especially on the beach.
Sunglasses can improve visual comfort and visual clarity by protecting the eye from glare.
Various types of disposable sunglasses are dispensed to patients after receiving mydriatic eye drops during eye examinations.
The lenses of polarized Karen Millen Blue Dress reduce glare reflected at some angles off shiny non-metallic surfaces, such as water. They allow wearers to see into water when only surface glare would otherwise be seen, and eliminate glare from a road surface when driving into the sun.
Sunglasses offer protection against excessive exposure to light, including its visible and invisible components.
The American Optometric Association recommends wearing sunglasses that block ultraviolet radiation (UV) whenever a person is in the sun to protect the eyes from UV and blue light, so as to protect them from serious eye problems. Its usage is mandatory immediately after some surgical procedures, such as LASIK, and recommended for a certain time period in dusty areas, when leaving the house and in front of a TV screen or computer monitor after LASEK. It is important to note that dark glasses without the function of blocking UV radiation can be more damaging to the eyes than not wearing eye protection at all, since they tend to open the pupil and allow more UV rays into the eye. Sunglasses have long been popular with celebrities and film actors who has a desire to mask their identity. Since the 1940s, sunglasses have been a fashion accessory for people of any ages, especially on the beach.
The only way to assess the protection of sunglasses is to have either the manufacturer or a properly equipped optician measure the lenses. Several standards for sunglasses allow a general classification of the UV protection, and manufacturers often indicate simply that the sunglasses meet the requirements of a specific standard rather than publish the exact figures.
The only "visible" quality test for sunglasses is their fit. The lenses should fit close enough to the face that only very little "stray light" can reach the eye from their sides, or from above or below, but not so close that the eyelashes smear the lenses. To protect against "stray light" from the sides, the lenses should fit close enough to the temples and/or merge into broad temple arms or leather blinders.
While non-tinted glasses are very rarely worn without the practical purpose of correcting eyesight or protecting one's eyes, sunglasses have become popular for several further reasons, and are sometimes worn even indoors or at night.
can be worn to hide one's eyes. They can make eye contact impossible, which can be intimidating to those not wearing sunglasses; the avoided eye contact can also demonstrate the wearer's detachment, which is considered desirable (or "cool") in some circles. Eye contact can be avoided even more effectively by using mirrored sunglasses. Sunglasses can also be used to hide emotions; this can range from hiding blinking to hiding weeping and its resulting red eyes. In all cases, hiding one's eyes has implications for nonverbal communication; this is useful in poker, and many professional poker players wear heavily tinted glasses indoors while playing, so that it is more difficult for opponents to read tells which involve eye movement and thus gain an advantage.
Fashion trends can be another reason for wearing sunglasses, particularly designer sunglasses from high-end fashion brands like Ray Ban that has particular shapes people would like to take as a fashion accessory. Fashion trends can also draw on the "cool" image of sunglasses and association with a particular lifestyle, especially the close connection between sunglasses and beach life. In some cases, this connection serves as the core concept behind an entire brand.