When a hotel develops a lending policy to provide patrons with sunglasses, it raises questions. The James Hotel recently introduced this feature in their New York hotel to supplement patrons as they enjoy the rooftop pool.

Besides pondering the luxury brand and the policy behind "forgotten returns," it makes many wonder: Why is this necessary?

While sunglasses can be fashionable, they serve a much more important function: protecting your eyes. And this becomes especially important as we enter July and August — the sunniest months of the year.

One of the greatest myths surrounding sunglasses is that they're only needed when it's sunny. Wrong. Ultraviolet (UV) rays can be just as harmful when the sun is setting or on cloudy days. It's even possible for the sun's rays to do maximum damage while it's raining.

According to a recent report by The Vision Council, "Protection for the Naked Eye: Sunglasses as a Health Necessity," 6 percent of people don't wear sunglasses on cloudy or rainy days, and 31 percent don't consider wearing sunglasses in winter, although reflective UV glare off snow and asphalt is harsh and damaging.

At the beach, sand can reflect up to 25 percent of UV rays and water reflects nearly 100 percent of the radiation. Those in Southern states tend to receive more intense solar rays because they are closer to the equator — and therefore closer to the sun.

During the summer months, it becomes essential to take care of your skin and eyes as well. UV radiation often leads to sunburns and skin cancer, but most people are oblivious to the impact of the sun's UV rays on our vision.

In the United States, UV levels are highest throughout summer, especially between 10 a.m. and 4 p.m. However, the level of UV entering the eye in the early morning (8-10 a.m.) and late afternoon (2-4 p.m.) is nearly double that of midday hours (10 a.m.-2 p.m.) at most times of the year because of the more direct angle of the sun's rays at those times.

More than half of Americans (58 percent) spend the most time outdoors from 2-6 p.m., a peak UV time for eyes.

A full day outside without protection can cause immediate, temporary issues such as swollen eyes and sensitivity to light. Consistent exposure can cause serious eye conditions such as cataracts, macular degeneration or blindness. Though one of the less common cancers, ocular cancers affects nearly 2,500 adults each year, according to the Ocular Melanoma Foundation.

The Vision Council created a special day on June 27 named "National Sunglasses Day" as a reminder that shades are a daily health necessity to promote long-term eye health. Individuals can lower the risk of potential eye diseases and tumors throughout the summer simply by wearing sunglasses.

UV protection is the most important aspect of sunglasses. Light-absorbing particles are embedded in the glass or on the surface, blocking the sunlight from entering your eye. Sunglasses typically have a tint factor of over 95 percent, though sunglasses should have at least 99 percent UV protection or block 100 percent of UV-A, UV-B and harmful blue light.

Ultimately, UV protection fights against radiation that can damage your eyes. Nearly 90 percent of Americans primarily look for comfort of fit in sunglasses, but it's most important to assure shades provide the right amount of protection from radiation.

Always remember to read the label. Unknown to many,not all sunglasses automatically have UV-A and UV-B protection included. When searching for sunglasses, focus on full UV protection over lens color.

There is no correlation between dark lenses and amount of UV protection, so the best sunglasses are not necessarily the darkest ones. And dark sunglasses without sufficient UV protection tend to be harmful, as the tint causes your pupils to dilate and allows more harmful ultraviolet light rays to enter the back of your eye. A higher tint factor works best for sensitive eyes in the sun.

Also, remember that polarized glasses are not equivalent to UV protection. They feature lenses that may reduce glare, but don't aid long-term ocular health.

Size does matter. The size and style of the lenses are also significant protective factors. Six diverse types of sunglass lenses and tinting exist. Small lenses provide less eye protection because they allow more sunlight to enter. Lenses that rest a far distance from the eyes also offer less protection. Choosing larger lenses that wrap fully around the eyes, protects them from angles that smaller lenses wouldn't.

And if you were looking for an excuse to splurge, a quality pair of sunglasses is a worthwhile investment in your family's health. Vintage shades or plastic sunglasses for children may not provide any filter from UV radiation. Children receive three times more exposure to the sun in than adults, which makes sunglasses even more vital.

High-end sunglasses undergo testing and are typically equipped with lifetime manufacturer warranties and a frame strong enough to add high-end sunglass prescription lenses.