Why do sunglasses protect the eyes?

The harm of ultraviolet rays

There are three types of ultraviolet rays in sunlight: UVA, UVB, and UVC. UVC is usually absorbed by the earth's atmosphere, while UVA and UVB are directly irradiated to the ground. Prolonged exposure to these ultraviolet rays can cause a variety of damage to the eyes, including:

1. Photokeratitis:

This is an inflammation of the surface of the eye caused by UVB, similar to sunburn on the skin.

2. Cataract:

Long-term exposure to ultraviolet rays increases the incidence of cataracts and causes blurred vision.

3. Macular degeneration:

UVA and UVB accelerate the degeneration of the macular area and seriously affect central vision.

4. Pterygium:

This is a growth on the cornea that is mainly caused by ultraviolet stimulation and may require surgical treatment.

The protective mechanism of sunglasses

High-quality sunglasses can effectively block 99% to 100% of UVA and UVB rays, thereby reducing the direct damage of these harmful rays to the eyes. The protective effect of sunglasses is mainly reflected in the following aspects:

1. Blocking UV rays:

High-quality sunglasses will indicate their UV400 protection level, which means that they can block all ultraviolet rays with a wavelength below 400 nanometers.

2. Reducing glare:

Polarized lenses can reduce glare from flat surfaces (such as water, snow, etc.), improve visual comfort and clarity.

3. Protect the skin around the eyes:

The skin around the eyes is thin and easily damaged by ultraviolet rays. Wearing sunglasses can provide additional protection and reduce the risk of wrinkles and skin cancer.

4. Prevent eye fatigue:

Strong light can cause the pupil of the eye to contract, increase the burden on the eye muscles, and cause eye fatigue for a long time. Sunglasses can reduce the intensity of light and make the eyes more relaxed.

How to choose the right sunglasses

Choosing the right sunglasses should not only consider their fashion, but also pay attention to their protective function. The following tips can help you make the right choice:

1. Check the UV protection label:

Make sure the sunglasses have a UV400 protection label that can block all harmful ultraviolet rays.

2. Choose the right lens color:

Gray lenses can reduce overall light without changing the color, while brown and amber lenses can increase contrast and depth perception, which is suitable for outdoor sports.

3. Consider the lens material:

Polycarbonate lenses are lightweight and impact-resistant, suitable for sports and daily use.

4. Ensure full lens coverage:

Large lenses and wraparound designs can provide better protection and prevent ultraviolet rays from entering from the sides.

Sunglasses are not only a fashion accessory, but also a necessity for protecting eye health. Choose high-quality sunglasses to give your eyes the best protection while enjoying the sun.