How to Choose Sunglasses that are Good for the Eyes?
Using sunglasses is a way to treat the eyes and not a means that works to cure vision. One function that is often overlooked is the function of protecting the eye from damage that can be caused by ultraviolet light.
Danger of Ultraviolet Rays
Exposure to ultraviolet rays for a period of time in the eye not only can cause damage to the skin surface of the eyelid. Parts of the eye, such as the cornea, lens, and retina also have the potential to suffer damage. In fact, ultraviolet light is thought to play a role in the onset of pterygium, cataracts, and macular degeneration.
Exposure to ultraviolet light directly that hits the cornea of the eye even risks causing keratitis. This condition is an inflammation of the cornea that gives a sore and swollen sensation in this part of the eye. Sunbathing too long in the sun or ultraviolet lights is one of the activities that may be a cause of keratitis.
How does ultraviolet light get to the retina? This condition is usually experienced by those who stare at direct sunlight during a solar eclipse without using special glasses to protect the eyes.
Because it has such an important function in protecting the eyes, the glasses are also required to have several conditions, both in shape and lens material. Good glasses must be able to block the entry of ultraviolet light. Therefore, glasses should have a large circular frame covering the eyes and surroundings. This is necessary, considering that light can enter from the sides of the eye which cannot be protected by ordinary frames.
Glasses that are good for protecting the eyes are those that have lenses that are able to block at least 75 percent of the incoming light. Eye health experts even recommend that the lens can filter out almost all ultraviolet A and B rays at once.
Look for lenses that have uniform color or darkness of the lens. To test, hold the glasses with your arms straight ahead. Look straight in the distance through your glasses. If the glasses are moved slowly horizontally and the object that appears to be curved and distorted means the lens is not eligible. But there is always something to remember, dark colored lenses are not a guarantee if the glasses cannot ward off harmful ultraviolet rays. It’s best to consult with an eye specialist first if you want to buy good sunglasses.
Types of sunglasses that are worth considering
Besides having a function to protect the eyes from exposure to ultraviolet light, several types and additional functions of sunglasses that must be considered.
1. Glasses with polarizing lenses
Sunglasses with polarized lenses have a function to reduce the glare caused by reflected light when illuminating the surface of water or snow. This type of glasses is useful for anyone who is driving during the day or those who like fishing.
2. Glasses with polycarbonate lenses
Polycarbonate material that is planted in the lens of a glasses has the function of protecting the wearer who likes to carry out extreme activities. Glasses with this type of lens suitable for use by those who need eye protection when exercising.
3. Glasses with blue blocking lens
Embedding lenses that are able to block the blue color is very useful to see distant objects located in the snow or objects blocked by fog. Hunters, sailors, pilots, and those who like to exercise skiing usually wear this type of glasses.
4. Photochromic-lensed glasses
Photochromic lenses can adjust to the amount of exposure to light. When exposed to large amounts of light, this lens will turn dark. Vice versa. At night, when there is no more sunlight, the lens will be bright. However, this change did not happen suddenly. It takes time to adjust the brightness of the lens to the amount of light exposure.
5. Glasses with gradient lenses
There are two types of gradient lenses, single and double. A single gradient lens with a darker part above is considered capable of reducing glare so that the wearer is able to see objects clearly. This type of glasses is not recommended for sports, but it is good if used while driving.
Meanwhile, double-gradient lens glasses, both used for activities in water or winter sports, but not while driving. This type of lens has darker parts at the top and bottom of the lens, while the center of the lens is brighter.
The thing to remember is that even the best glasses are not able to protect the wearer from too bright light and strong intensity. Therefore, those who are familiar with strong light when working, such as welding, must wear special protection. Special protection is also needed when looking at direct sunlight, for example to watch a solar eclipse.