At least 2.2 billion people worldwide have some form of near or distance vision impairment. From wire-framed reading glasses to prescription sports eyewear, millions wear corrective lenses to improve general eyesight and enhance personal style. However, not everyone understands how these everyday accessories really work.

Key Takeaways

• Eyeglasses are often used to correct vision problems. However, beautifully crafted frames from independent designers can also be used as a fashion statement.
• Eyeglasses are worn to correct refractive errors, such as myopia or hyperopia, which occur when the eye cannot correctly focus light on the retina.
• Prescription lenses bend light as it enters the eye, allowing it to correctly focus on the retina.
• Lenses are usually concave, convex, or cylindrical, depending on the type of vision correction needed.

Keep reading to learn more!

See Related: How To Remove Scratches From Glasses

What Are Eyeglasses?

Eyeglasses can be a powerful fashion statement, especially when you wear handcrafted and high-quality frames from independent designers. Typically, eyeglasses are worn for the primary purpose of correcting vision problems.

Eyeglasses can help your eyes compensate for what they can't do on their own. They can help with a variety of vision issues, including nearsightedness and farsightedness.

The History of Glasses

Archeologists have traced back eyeglasses to the late thirteenth century in Italy. However, many historians credit Roger Bacon, an English philosopher and friar, with the invention of the modern-day spectacle. This process was outlined in his book Opus Majus, though there wasn't any actual evidence that Roger Bacon indeed crafted the first spectacles.

The first pairs of eyeglasses were made with two magnifying glasses connected with a bridge piece. In the late eighteenth century, bifocals were invented. Later, John McAllister opened the first American optical shop.

Over the years, the design and function of frames and lenses have significantly improved.

Nowadays, eyeglasses are comfortable and lightweight yet durable and sturdy. Lenses are made with materials like CR-39 and Trivex that offer superior vision correction with minimal distortion. Frames crafted by independent designers and artisans feature exceptional craftsmanship, high attention to detail, and gorgeous artistic details.

Photo Credit: @jacquesmariemage

The Human Eye

Eyeglasses are worn to correct vision problems. Vision problems usually occur due to a refractive error. Refractive errors make it difficult for the eye to focus light correctly on the retina.

The retina is a cell layer that reacts to incoming light and communicates with the brain. However, for this to happen, the retina relies on the cornea and lens of the eye. As light enters the eye, it first hits the cornea. The cornea and lens reduce the incoming image size so that it fits onto the retina while focusing light directly onto the retina.

What is Refraction?

To understand how glasses work, you'll need to understand refraction. Refraction is the way in which a light wave changes in speed or direction when traveling through different materials. If your eye is unable to focus light correctly onto the retina, it can lead to a refractive error and vision problems.

Refractive Errors

The most common types of refractive errors are:

• Myopia: Myopia, or nearsightedness, happens when the incoming image is focused in front of the retina. This can cause things to look fuzzy or out of focus when seen from far away.
• Hyperopia: Hyperopia, or farsightedness, happens when the incoming image is focused behind the retina. This can cause things to look fuzzy or out of focus when seen close up.
• Astigmatism: Astigmatism is caused by an uneven cornea or lens surface, leading to distortion and a second focal point.
• Presbyopia: Presbyopia can occur due to the eye's natural aging process. Over time, the lens will struggle to correctly focus light on the retina and cause blurry vision when viewing objects close.

Photo Credit: @carolineabram.paris

How Do Glasses Work?

Your eye consists of the pupils, cornea, retina, and lens. This complex network allows light to be transferred to the optic nerve. Corrective lenses work by focusing light directly on the retina by bending light as it enters the eye.

For example, corrective lenses with a minus (-) prescription may fix myopia by directing light further back. Corrective lenses with a plus (+) prescription may fix hyperopia by directing light closer to the front. This helps correct any refractive error by accurately directing light onto the retina.

What Type of Corrective Lenses Do I Need?

Around 66% of United States adults use some form of vision correction, whether that be contact lenses or prescription eyeglasses.

It's recommended you visit the optometrist every one to two years. You'll get some valuable insight into your eyesight and health, and you'll likely discover if you are in need of glasses. If you have blurry vision, frequent headaches, or eye strain, you might be in need of corrective eyewear.

Glasses are used to correct refractive errors. They are often classified as either convex lenses or concave lenses. There are also cylindrical lenses and prism lenses.

Convex lenses are marked with a plus (+) prescription and correct farsightedness as they are thick in the center and thin on the edges. Concave lenses are marked with a minus (-) prescription and correct nearsightedness as they are thin in the center and thick on the edges. Cylindrical lenses bend light into one single line.

When you visit your optometrist, you'll figure out the right type and style of corrective eyewear for your lifestyle and vision needs.

Bonus: The Different Types of Glasses Lenses: A Guide To Lens Types

Photo Credit: @nativesonseyewear

Final Thoughts

Glasses might seem simple at first glance. However, there are countless types and styles of lenses and frames that can be used to correct a variety of vision problems. Be sure to keep your eyewear clean and well-maintained, and visit your optometrist when it's time for your annual eye exam!

Keep Reading: A Simple Guide To Understanding Your Eye Prescription

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Oculus Eyecare is Seattle’s premier optometry practice and optical boutique for those looking to see and be seen in a new way. Located in South Lake Union on Denny Way, Oculus Eyecare offers comprehensive eye care services and exams for individuals and families in Seattle. Click here to schedule an appointment or a personal styling session. To stay connected and learn more, follow us on Facebook, Instagram, and X/Twitter.