Facts About Sunglasses

Various Types of Sunglasses

Far beyond any of the fashionable trends and the seemingly always important ‘cool’ factor, sunglasses actually play a rather important and perhaps even unseen part in our everyday lives. Our world is bathed in the light of the sun, and within that light dangers lurk that can compromise our precious eyesight and impact the quality of our lives.

Here we’ll take a closer look at what these natural dangers are and the types of light that can affect our eyes. We’ll talk about some of the eye diseases that can result from this light and get some pointers on the types of sunglasses that optometrists and opticians recommend. They’re our eyes and our only window on the world, so let’s use them to peer through the special lenses we call sunglasses to get a safer and better view.

The History of Sunglasses

Attempts to block the glare of the sun have been around since the late 13th century when the first glassmakers in Italy and Germany began to fashion convex lenses into what were then called ‘spectacles’ to correct vision.

Lens makers soon followed with tinted glass to help cut the glare of natural light through their lenses. This may have been an adaptation of the 12th century Chinese who used small thin panes of natural smoky quartz held with bamboo to reduce glare in bright sunlight.

Nowadays, we even have prescription sunglasses that not only block the sun’s rays but also corrects vision problems at the same time!

What Types Of Light Are There?

Sunset Displaying Light

Our planet is only about 93 million miles from the sun, a 900,000 mile wide ball of hydrogen. The sun produces heat and light by burning its hydrogen and converting it into helium with the power of a half million atomic bombs per second. Cosmologically speaking, we are extremely close to our host star and we’re bathed not only in its beneficial light, but in its rather dangerous light waves as well.

The sun produces three types of ultraviolet light beyond our visible spectrum, UVA, UVB and UVC rays, and they vary in importance here on planet Earth. Here are the basics:

  • UVA rays have a longer wavelength and pass through glass very easily. Experts disagree about UVA’s potential to damage our eyesight.
  • UVB rays are the most dangerous, but can’t pass through some glass. This makes sunglasses very important for eye protection from UVB.
  • UVC rays are of a wavelength that is largely blocked by our upper atmosphere, making them the most benign of the suns UV light.

Why Do We Need Sunglasses?

As mentioned, UVB rays are one of the most sinister forms of ultraviolet light produced by our sun. These rays are responsible for some rather debilitating eye diseases. This includes photo-keratitis which is akin to sunburn of the cornea, pinguecalae, an inflammation of the sclera or eyeball, and permanent retinal damage which destroys the ability of the eye to properly focus incoming light.

Sunglasses provide our eyes with the protection they need because the damaging effects of UVB are filtered out or blocked from entering the eye. This allows our eyes to gather only the light needed in the visible wavelength spectrum, focus it and allow us to see the world more safely. Without sunglasses, we’re taking unnecessary chances with our vision and our quality of life.

What Types Of Sunglasses Are There?

There are of course many types of sunglasses, whether they are store bought or provided by your local optician. Of course, if you already wear corrective lenses, your optician can easily recommend the type of sunglass lenses that will be the most beneficial for your sight requirements. Either way, here are a few of the major types of lenses.

  • Blue-blockers block blue light and usually have an amber tint. They sharpen the background and are excellent for skiers, boaters and pilots.
  • Polarized lenses cut reflective glare and are very effective for those who engage in snow and water sports activities.
  • Anti-reflective sunglass coatings reduce the glare caused by light that reflects off the back of the sunglass lens and reduces squinting.
  • Mirror coatings work by reducing the amount of bright light at the surface of the polarized lens, so bright conditions are more controlled.
  • Gradient sunglasses have lenses with varying amounts of tint to control incoming light at the top or bottom of the lens. This enables viewing in some low and bright light conditions more comfortably.

How Can I Make The Right Choices?

First of all, and especially when it comes to your eyes, it’s always far better to be safe than sorry. Two basic rules should be at the top of the list. Never purchase any sunglasses that do not have UV protective qualities. The glasses should be labelled indicating that they are 100% effective in blocking dangerous UVA and UVB rays.

Also, never think that the darker the lens, the more protection it affords. There are some cheap sunglasses on the market that sell well simply because they are dark, but if the lenses aren’t UV rated, they will not properly protect your eyes.

Whatever your age, lifestyle or environment, good sunglasses are absolutely essential for proper eye protection as well as to improve contrast and see more clearly. When thinking about your next pair of sunglasses one of the best decisions you could make would be to consult your local optician. They can assist you in selecting the right sunglass lenses and tints to compliment you and your ability to see more safely and clearly than ever before.