Sunglasses are often considered to be a fashion accessory. However, they are not simply a stylish statement. On the contrary, sunglasses are an important accessory for anyone, young or old, who spends time outdoors. Sunglasses protect the eyes from the sun's harmful rays, which in turn, prevents eye diseases as well as skin cancer around the eyes. Additionally, sunglasses reduce the glare caused by the sun, which prevents the eyes from watering and squinting too much, often causing headaches. Sunglasses promote healthy eyes, which leads to happier wearers.
Evolution of Sunglasses
Sunglasses have roots set in ancient China and Rome. During court trials, Chinese judges wore dark quartz over their eyes to mask their expressions. And famous Roman emperor Nero wore gemstones over his eyes to prevent sun glare while watching outdoor sporting events. In the 1700s, English optician, James Ayscough, invented blue and green-colored spectacles to treat certain vision problems, and these are considered to be a precursor to modern-day sunglasses. In 1929, Sam Foster, founder of the American company, Foster Grant, invented sunglasses to shield the eyes from the bright summer sun. And he sold the first pair of Foster Grant sunglasses on the Boardwalk in Atlantic City, New Jersey. Tourists flocked to his stand, and by 1930, sunglasses were all the rage. During this time, actors and actresses glamorized the look of sunglasses, thus increasing the popularity of the necessary accessory.
However, sunglasses were not just fashionable; they also served as a highly functional tool during World War II. In the mid-1930s, the Army Air Corps commissioned the optical firm of Bausch & Lomb to develop an effective spectacle that would protect pilots from the dangers of high-altitude sun glare. Consequently, company physicists and opticians produced a unique dark-green tint that absorbed light in the yellow band of the spectrum. This polarized lens technology was created by Edwin H. Land, founder of the Polaroid Land Corporation. In addition to this, they also designed a slightly drooping frame perimeter to shield an aviator's eyes, which consistently glanced downward toward a plane's instrument panel. Fliers were issued the shades for free. And in 1937, the public was able to purchase the model that banned the sun's rays as Ray-Ban aviator sunglasses.
Importance of Sunglasses
Sunglasses serve several functions for wearers. Owners should be aware of the many advantages to wearing sunglasses daily.
Sunglasses help protect eyes from ultraviolet (UV) radiation. This type of radiation from sunlight has been linked to the development of cataracts, eye cancers, and age-related macular degeneration, among other eye diseases. Additionally, sunglasses protect the delicate skin around the eyes from these rays that also cause wrinkling, premature aging, and skin cancer. Quality sunglasses block 99 to 100 percent of the sun's harmful UV rays.
The sun's glare is especially strong on surfaces such as water, snow, and vehicle windshields. These light reflections can be very distracting and significantly impede vision. This is very dangerous when driving, riding a motorcycle or bicycle, skiing, or boating. Sunglasses help decrease glare for safer vision. Polarized sunglasses are especially effective at cutting reflective glare when the sun bounces off of certain surfaces.
Sunglasses act as a barrier between the wearer's eyes and environmental conditions. When wearing sunglasses in windy conditions, they reduce the rate of evaporation of tears and help keep eyes moist and comfortable. If the wearer uses contact lenses, this protection is especially needed so that lenses do not dry out. Further, sunglasses prevent windblown particles, such as dust and dirt, from getting into the eyes and causing a corneal scratch. Close-fitting, wraparound sunglasses are very effective at decreasing the potential for dry eyes and eye injuries from windblown particles.
Headache and Eyestrain Reduction
The pupil at the front of the eye controls how much light reaches the light-sensitive retina in the back of the eye. In dim light, the pupil gets bigger, or dilates, to allow more light to enter. In bright light, the pupil gets smaller to prevent too much light from striking the retina.
In really sunny conditions, the pupil is not able to constrict small enough to reduce light to a comfortable level. This causes a person to squint, thus reducing the space between the upper and lower lids and blocking light. Continual squinting causes muscle fatigue. Additionally, constant constriction of the pupil can lead to headaches and eyestrain. Because sunglasses reduce the amount of light that reaches the eyes to a more appropriate level, the need for squinting and severe pupil constriction is eliminated. Therefore, comfort is increased and headaches and eyestrain are reduced.
The eyes require a certain range of ambient light for good vision, and too much light is just as bad as too little. Excessive brightness causes glare, light-induced "bleaching" of the retina, and squinting. All of these can temporarily reduce visual acuity. On bright sunny days, sunglasses reduce the amount of light that reaches the retina to more manageable, optimal levels for clear, comfortable vision.
When checking out sunglasses, there are a few qualities that should be taken into consideration so that buyers get the best pair for them.
1. Ultraviolet Protection
Ideally, buyers should find a pair of sunglasses that block out 99 to 100 percent of ultraviolet rays. Ultimately, the shades should block both UVA and UVB since these rays can cause harm to the eyes. Buyers should look for sunglasses labeled "UV 400," which blocks all light rays with wavelengths up to 400 nanometers, which covers all of UVA and UVB rays. Doing so will keep eyes healthier in addition to also preventing premature aging of the thin skin around the eyes.
2. Polarized Lens Protection
Buyers should also look for lenses that are polarized. Rather than simply making the environment darker, polarized lenses reduce glare from surfaces like water, glass, and snow. They are much better than standard tinted sunglasses for driving and certain sports since they allow the wearer to see more clearly.
3. Lens Tints
Although polarized lenses' offer the best sun glare protection, some opt for tinted lenses instead. These tints are applied to sunglasses' lenses to help absorb light as it passes through them. The color chosen is a matter of personal taste, but there are a few important color-related benefits to consider.
- Gray Lenses: These reduce brightness, but do not distort color.
- Brown and Amber Lenses: These tints reduce some sun glare, including the glare created by the blue frequency in sunlight, which can make the environment seem hazy. However, brown and amber tints distort colors more than gray tints.
- Yellow Lenses: These tints reduce the haze from blue light better than brown lenses, so they really are good for sharpening up images, but they cause more color distortion.
- Green Lenses: These decrease glare and aid in filtering out some of the blue light. They also offer good contrast between objects.
- Rose Lenses: These can be a smart choice for those who are active in water sports or other outdoor activities, because they provide good contrast for objects viewed against blue or green backgrounds.
4. Polycarbonate Lenses versus Other Materials
Tinted or polarized, polycarbonate lenses are an ideal plastic for sunglasses lenses. Constructed from compressed plastic tubes, these lenses are shatter resistant. If they do break, the tubes roll upon each other instead of cracking into countless pieces like glass or other plastics. This equals increased safety for the wearer in case the shades should break.
Sunglasses can also be made out of CR-39, which is another plastic, but it is mostly used in prescription lenses. Glass is also an option for lens material, but it is heavy to wear and not as safe as the polycarbonate lenses.
Currently, the most fashionable sunglasses boast large frames. As such, the original design of sunglasses can be said to be making a comeback as they also had wide frames. However, consumers should be wary of purchasing large sunglasses, because wearing a large, heavy frame can give some people a headache as the weight causes stress on the bridge of the nose, the tops of the ears, and or the temples. Wearing lightweight sunglasses reduces or eliminates this problem, and users should be sure to try on frames first before buying. A good choice in frame material is titanium, because these are lightweight, flexible, and durable. They are also non-corrosive and hypoallergenic, thus allowing it to have a longer lifespan for daily sunglasses wearers.