Sunglasses

Sunglasses help your eyes. They stop bright light from the sun. This keeps your eyes from hurting.

Long ago, people used other things. Some used bone with tiny slits. This helped them see in the snow.

In China, people used dark stones. These stones helped hide their faces. They also stopped bright glare.

Today, we use special lenses. These lenses block bad rays. This keeps our eyes very safe.

Do you wear them in the sun?

Sunglasses protect our eyes from bright sunlight. They stop light from causing discomfort. They also block ultraviolet radiation, or UV. UV is a type of light we cannot see. This light can cause serious eye problems.

People have protected their eyes for a long time. The Inuit people used snow goggles. These were made from walrus or caribou ivory. They had narrow slits to block sun rays.

In China, judges used Ai Tai. These were dark stones called smoky quartz. They used them to hide their faces. They also used them to stop glare.

Modern sunglasses have many special parts. Some have polarized lenses. These lenses reduce glare from shiny things like water.

It is important to choose the right pair. Dark lenses must block UV rays. If they do not, they can be bad. This is because they make your pupil open wider. This lets more harmful light in.

Sunglasses are special eyewear designed to protect our eyes. They stop bright sunlight from causing discomfort or damage. These glasses can also help us see more clearly. Some lenses are colored, darkened, or polarized to help with vision.

It is very important to wear sunglasses that block ultraviolet radiation, which people call UV. UV is a type of light that can cause serious eye problems. Dark glasses that do not block UV can actually be harmful. This is because they make your pupil open wider. A wider pupil lets more harmful rays into your eye.

Sunglasses work in several different ways to protect you. Many lenses filter out UV rays and blue light. Some lenses are polarized to reduce glare. Glare is the bright light that bounces off shiny surfaces like water or roads. Polarized lenses help you see into the water more easily.

You should also look for a good fit. The lenses should sit close to your face. This stops stray light from entering through the sides. Broad temple arms can help block this side light.

People have found ways to protect their eyes for a very long time. As far back as the 13th century, Inuit people made snow goggles. These were made from walrus or caribou ivory. They had narrow slits to block harmful reflected rays from the snow.

In China, people used Ai Tai in the 12th century. These were made from smoky quartz called "dark clouds." Judges used them to hide their facial expressions in court.

In the 18th century, Venetian women wore "gondola glasses." These were tinted, mirror-like glasses to protect against water glare.

Many famous names and dates are part of sunglasses history. In 1772, the scientist Antoine Lavoisier was shown wearing them. By 1929, Sam Foster made inexpensive sunglasses from celluloid. He sold them on the boardwalk in Atlantic City, New Jersey.

In 1936, Edwin H. Land began working with polarized filters. By 1937, about 20 million sunglasses were sold in the United States. Today, Xiamen, China, is a huge producer of these glasses. Their port exports 120 million pairs every year.

You might recognize sunglasses from movies or even the sky. In the 1920s, movie stars made wearing them very popular. Pilots also began using them to help them fly. Some people even use special solar viewers to look at a solar eclipse. Regular sunglasses are not safe enough for looking directly at the sun. Just like you use an umbrella for rain, sunglasses act as a shield for your sight. They help you enjoy the bright world safely.

Sunglasses are a specialized form of protective eyewear. They are primarily designed to prevent bright sunlight from damaging or discomforting the eyes. Beyond mere protection, they can also function as visual aids. Some versions feature lenses that are colored, darkened, or polarized to improve how a person sees the world.

Because they manage light, they are essential for both health and comfort in bright environments.

The mechanism of protection involves filtering specific parts of light. The most critical function is blocking ultraviolet radiation, often called UV radiation. Experts recommend sunglasses that filter out 99% or more of UVA and UVB light. These are often labeled as "UV400" because they block wavelengths up to 400 nm.

Another important function is managing high-energy visible light, or HEV light. Some manufacturers now design lenses specifically to block this blue light. This is particularly important for children, as their ocular lenses may transmit more HEV light than those of adults.

Different types of lenses offer different benefits. Polarized sunglasses use a special filter to reduce glare. Glare is the bright light that reflects off non-metallic surfaces like water or roads.

By reducing this reflected light, polarized lenses allow a person to see more clearly into water or down a sunny road. Other sunglasses focus on shade and color. For example, some people use amber-tinted lenses to manage light sensitivity. However, it is vital that dark lenses also block UV radiation. If dark lenses do not block UV, they can be more harmful than wearing no protection at all. This happens because the darkness causes the pupil to open wider, allowing more unfiltered radiation into the eye.

Physical design also plays a role in how well sunglasses work. A good fit is a visible way to test quality. The lenses should sit close enough to the face to block "stray light." This is light that enters from the sides, above, or below the lenses.

To prevent this, sunglasses often feature broad temple arms or leather blinders. These components act as shields to ensure light only enters through the protected lens area.

The history of eye protection stretches back many centuries. As early as the 13th century, Inuit people crafted snow goggles. These were made from flattened walrus or caribou ivory and featured narrow slits. These slits blocked harmful reflected rays to prevent snowblindness. In China, 12th-century users wore Ai Tai, which means "dark clouds." These were made from flat panes of smoky quartz. Chinese judges used these crystal glasses to hide their facial expressions while questioning witnesses.

Later, in the 18th century, Venetian women wore "gondola glasses." These were tinted, mirror-like frames used to shield eyes from the glare of canal water.

Modern sunglasses emerged through various scientific and commercial milestones. In 1772, the scientist Antoine Lavoisier was depicted wearing tinted glasses while working with amplified sunlight.

By 1899, the company Rodenstock GmbH produced glasses intended specifically to shield eyes from UV light. In 1929, Sam Foster produced inexpensive mass-produced sunglasses made from celluloid. He sold them on the Atlantic City Boardwalk under the name Foster Grant.

By 1936, Edwin H. Land began experimenting with the patented Polaroid filter, leading to polarized sunglasses. In 1937, approximately 20 million sunglasses were sold in the United States alone.

Today, sunglasses are both a medical necessity and a global industry. They are mandatory for patients immediately following surgical procedures like LASIK. They are also recommended for use in dusty areas or when using computer monitors after LASEK. The industry is massive, with Xiamen, China, serving as the world's largest producer. As of 2008, its port exported 120 million pairs of sunglasses each year. From protecting pilots in the aviation sector to helping movie stars, sunglasses have become permanent cultural icons.