SunGlass Information
Archive for the ‘Eye Health’ Category
Macular Degeneration - A big name for a big problem
As we continue reduce the ozone layer the effects of UV rays on the mucus membranes continue to increase. Our parents didn’t think about SPF clothing or Sunscreen, they went out with oil in the hottest part of the day without another thought. People during thier time contracted Cancer and they’re deaths were described as “consumption” . The first sunglasses did little to protect the wearer and were more designed for fashion. And Sunscreen was not even a consideration.
Times have changed and now we know that UV rays can cause irreversible damage to both the skin and eyes. And we now have the technology to protect both. Experts suggest that we use Sunscreen with at least a SPF (sun protection factor) of 35 or more. And it has been proven that sunglasses without UV protection can lead to Macular Degeneration. So it is important to pick Sunglasses that have 100% AVA and AVB protection.
What is the real cost of cheap Sunglasses?
We’ve all been tempted to buy those cool looking sunglasses at the department store and when you add it to your other purchases you barely notice how much they cost. But what is the real cost of those sunglasses? I’m not talking about the number on the price tag I’m referring to long term costs associated with poorly manufactured sunglasses. These products rely on flash and often spend more money on the frames paying little attention to the lenses. Lets look at some of the costs of these dangerous impostors.
Exposure to ultraviolet rays is the leading cause of cataracts in adults but this damage can begin while we are children. They also can cause skin cancers on the eyelids and around the eyes. In addition to these problems excessive exposure to glare can cause eye fatigue and headaches. Think about the cost associated with an Opthamologist , Dermatologist or even an Oncologist.
I think it’s clear that purchasing quality eyewear from a reputable company is much cheaper than those department “cheapies”.
Teaching your children to wear sunglasses may be more important than giving them a college fund.
All children should be taught to wear sunglasses, especially between 10 AM and 2 PM, when ultraviolet exposure is the most dangerous. This is true even for children with darker eye colors, even though their darker pigments afford partial protection. Of course, children with light-colored eyes need sunglasses all the more. Ultraviolet exposure is at its peak when children are at high altitudes, snow-covered landscapes, bright sandy beaches, or near reflective bodies of water.
Most people wear sunglasses to reduce glare. This is trivial compared to the long-term protection they afford for the precious ability to see. Parents can set a good example for their children by wearing sunglasses at the appropriate times.
All sunglasses are not the same. Effective sunglassesshould block both UVA and UVB radiation. Large lenses that fit close to the eyes are best. Those that block visible blue light are even safer. Thankfully, all sunglasses block UVB radiation. A great many sunglasses, however, do not afford UVA protection. Expensive brand names and polarizing lenses are no guarantee. The sunglasses must be measured to block 99% to 100% of UVA or UV400 (400 nm is the wavelength of UVA radiation).
Ordinary sunglasses make the situation WORSE! The dark lenses cause the pupils to dilate, allowing more of the dangerous UVA radiation to damage the lens and the retina.
Of course, children will break and lose sunglasses with remarkable rapidity. Thankfully, suitable sunglasses are quite cheap. I bought another pair yesterday for under five dollars that blocked blue light and had 100% UV400 protection.
Expensive brands may be more stylish, but they confer no advantage when it comes to eye health.
Courtesy WebMD.com
Actually you have three choices when it comes to lens composition: Glass, Plastic or Polycarbonate. All have advantages and disadvantages we will discuss each so you can determine which is best for you.
Glass lenses provide the best scratch resistance and highest optical clarity. They are, however, 2-3 times as heavy as plastic or polycarbonate lenses and, while they are tempered for impact resistance, can shatter or break if struck by an object. These types of lenses are suitable for people who value durability and clarity but are not great for people involved in high speed sports or activities where something could strike your lenses or face.
Plastic lenses are significantly lighter than glass lenses, and thus, may be more comfortable to wear for extended periods of time. Also, while not shatterproof, these lenses are also more shatter resistant than glass. Disadvantages include average optical clarity and less scratch resistance. These types of lenses are great for customers looking for a lightweight, affordable pair of sunglasses.
Polycarbonate lenses are shatterproof and extremely lightweight. Their primary drawback is that the material is very soft and is the least scratch resistant material used. These lenses are great for active people involved in sports. Because they are lightweight they will stay put when moving around. The shatterproof lenses will also provide protection from not only UV rays, but also impact from objects or in case of an accident or a fall.
Macular degeneration is the leading cause of severe vision loss in people over age 60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye. Because the disease develops as a person ages, it is often referred to as age-related macular degeneration (AMD). Although macular degeneration is almost never a blinding condition, it can be a source of significant visual disability.
There are two main types of age-related macular degeneration:
- Dry form. The “dry” form of macular degeneration is characterized by the presence of yellow deposits, called drusen, in the macula. In general, drusen do not cause changes in vision; however, as they grow in size and increase in number, they may lead to a dimming or distortion of vision that people find most noticeable when they read. In more advanced stages of dry macular degeneration, there is also a thinning of the light-sensitive layer of cells in the macula leading to atrophy, or tissue death. In the atrophic form of dry macular degeneration, patients may have blind spots in the center of their vision. In the advanced stages, patients lose central vision.
- Wet form. The “wet” form of macular degeneration is characterized by the growth of abnormal blood vessels from the choroid underneath the macula. This is called choroidal neovascularization. These blood vessels leak blood and fluid into the retina, causing distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision. These abnormal blood vessels eventually scar, leading to permanent loss of central vision.
Most patients with macular degeneration have the dry form of the disease and will not lose central vision. However, the dry form of macular degeneration can lead to the wet form. Although only about 10% of people with macular degeneration develop the wet form, they make up the majority of those who experience serious vision loss from the disease.
It is very important for people with macular degeneration to monitor their eyesight carefully and see their eye doctor on a regular basis. An remember, use of sunglasses with good UV protection can reduce the suns damage.
source: WebMD.com
When asked what sunglass qualities where important for Bowfishing Robert Grider, O.D. wrote this article that first appeared on Bowhunting.com.
#1 Polarization
Sunglasses must use true polarized lenses to remove the glare which hinders our ability to see into the water. Most polarized sunglasses are marked, if it is not clearly stated then they are probably not polarized. Please realize that like most things in life, there are different qualities of polarization and the more expensive the lenses the more likely they are of higher quality.
#2 Quality Optics
Try to make sure the sunglass lenses optics are of decent quality. I have seen countless cases where people present to my office complaining of headaches only to find that the poor optics of their sunglasses are the source of the problem. To test your glasses you can hold the glasses up several inches from your face while viewing a consistent grid like a sheet of graph paper and by turning the lenses slightly and moving the glasses slowly back and forth and up-down while looking for areas of curved lines and/or distortion of the distant pattern. Please understand that many of today’s wrap-around type of sunglasses will have at least some distortion in the very extreme side or periphery of the lenses this is unavoidable but you would like this to be as minimal as possible.
#3 Lens Tint
I am often asked which color sunglasses work best for bowfishing and to be honest, there is no single best color for every person and every shooting situation. Gray lenses tend to alter the color vision spectrum the least in relation to the human eye and make for a good all-around pair of sunglasses that might be used for other activities as well. (see Selecting the Correct Tint Blog)
#4 Ultra violet ray protection
Make sure the sunglasses you purchase have the ability to absorb 100% of the sun’s harmful ultra violet rays. Remember while on the water you are actually getting a double dose of UV, those rays directly from the sun and those rays that are bouncing off the waters surface. Significant exposure to UV rays has been shown to cause the serious eye damage such as development of cataracts and Age-Related Macular Degeneration which happens to be the leading cause of blindness for those over 65 years old.
#5 Glass or plastic lenses and a word on cost.
In general, plastic lenses (polycarbonate lenses) scratch more easily than glass lenses but they tend to weigh half as much as glass and are much more shatter resistant than glass lenses making them safer if used around flying objects (think snap-back of an arrow). Many plastic lenses will have a scratch resistant coating with the more expensive plastic lenses having a better scratch resistant coating. Both plastic and glass can offer exceptional optics however and when you figure in the safety factor plastic comes out ahead.
When it comes to costs you don’t have to spend $200-$300 for a pair of Maui Jims in order to get a good pair of sunglasses with quality optics. These brands often have a tremendous amount of price mark up and the optics and polarization are pretty much the same in a much less expensive pair of Gargoyles or Coyote Sunglasses. The law of diminishing returns often applies to the price of sunglasses.
And finally, remember that after your bow and arrow, your polarized sunglasses are the next most important piece of gear when it comes to daytime bowfishing, so choose with care.
Sam Foster is widely recognised as the creator of the modern day Sunglasses. His company, Foster Grant was started in 1919 producing Ladies hair accessories. Then in 1929 he began selling his glasses at Woolworth’s on the Atlantic City Boardwalk. By 1934 they introduced injection molding enabling Foster Grant to grow from a regoinal company to a national one.
In the 1930s, the Army Air Corps commissioned the optical firm of Bausch & Lomb to produce a highly effective spectacle that would protect pilots from the dangers of high-altitude glare. Company physicists and opticians perfected a special dark-green tint that absorbed light in the yellow band of the spectrum.
With World War II brewing in 1936, Ray Ban (a Baush & Lomb Company) designed anti-glare aviator style sunglasses, using polarized lens technology newly created by Edwin H. Land, founder of the Polaroid Corporation.
They also designed a slightly drooping frame perimeter to maximally shield an aviator’s eyes, which repeatedly glanced downward toward a plane’s instrument panel. Fliers were issued the glasses at no charge, and the public in 1937 was able to purchase the model that banned the sun’s rays as Ray-Ban aviator sunglasses.
Summer Sunlight Linked to Macular Degeneration
In a recent study, researchers looked at the association between sunlight exposure and the 10-year risk of age-related macular degeneration among a large group of adults aged 43 to 86 years who were first examined between 1988 and 1990 as a part of the Beaver Dam Eye Study.
The results appear in the May issue of The Archives of Ophthalmology.
Researchers found that people who spent more than five hours a day in the summer sun in their teens, 30s, and after age 40 were more than twice as likely to develop early age-related macular degeneration compared with those who reported spending less than two hours per day of sunlight during the same periods.
In addition, those who got five or more hours per day of summer sun were more than three times as likely to develop increased retinal pigment, a condition commonly associated with age-related macular degeneration.
But the study showed wearing hats or sunglasses at least half of the time reduced the risk of developing deposits on the retina by 50% among those who reported the highest sun exposure levels.
The study also found that people who had more than 10 severe sunburns in their youth were two and a half times more likely to develop an increase in pigments found in the retina.
Source: WebMD