Sunglasses Lens Categories: How dark are my lenses?

The sunglasses that we choose are important for a variety of reasons. It plays a major role in how we look and feel when wearing them. You’re able to flaunt your personality with a pair of sunglasses that completes your outfit.

But more importantly, sunglasses are designed to protect your eyes from the sun and its harmful UV rays. There are different types of sunglasses lenses with various lens options that you’ll have to choose from in four categories of darkness. Every single choice that you make affects the way that you see the world when wearing them and provides a different level of protection from the outside elements. 

You don’t have to sacrifice style for optimal protection. So if you are looking for 100 percent shades, polarized glasses, or designer sunglasses that show off your personality it’s important to know when is best to wear them.

What are the sunglasses lens categories?

Whether you’re looking for lenses for your prescription or non-prescription lenses there are a variety of tints and darkness levels that you’ll have to choose from. And depending on the severity of the darkness will determine how much visible light is absorbed. 

Visible light absorption is referred to as ABS% and it determines the amount of light that is absorbed by the lens. This number will be between 1% and 100%. The lower the number the more light will reach your eyes. The higher the number the less light will reach your eyes.

Category 1 sunglasses 

Category 1 lenses are not technically considered to be sunglasses. These are typically yellow or pale/light tint. Category 1 sunglasses have a light transmission percentage of 44 to 80 percent.

These provide no type of protection from the sunny conditions. However, they are ok in overcast conditions and low sun exposure. They will provide limited sun glare reduction and may have some UV protection.  Mostly these are considered to be fashion sunglasses 

Yellow tints make the surroundings look brighter, and may have some color distortion. However, their contrast-enhancing property makes them great for night driving or sports. 

Category 2 sunglasses

Category 2 sunglasses are typically tinted with orange, rose, blue and red lenses. Category 2 sunglasses have a sunglasses light transmission percentage of 19 to 43 percent.

They do provide a medium level of protection against glare, and some are good for partially sunny conditions.

Rose-colored glasses may help to improve visibility when driving and increase depth perception as well as detail. And may help to reduce and prevent migraines by filtering certain wavelengths of light from fluorescent fixtures which have been known to trigger migraines.

Category 3 sunglasses

Cat 3 sunglasses provide protection against sun glare, making them perfect for many activities because they reflect the light off of water or snow. They also protect against the strong sun brightness. This category is found in many non-polarized and polarized lenses. 

Category 3 sunglasses have a sunglasses light transmission percentage of 9 to 18 percent. Typically these are brown and gray lenses.

Brown lenses help you to better see the contrast, and give your eyes comfort in sunny conditions. Often brown lenses are recommended for people with near-sightedness or myopia. Gray tint helps your eyes deal with fatigue and is generally good for all purposes.

Category 4 sunglasses

Category 4 sunglasses are typically a very dark gray or brown lens. This sunglasses category is best for where the sun is intense or there are high glare conditions. These wouldn’t be used for common conditions such as driving due to tint density.  

Category 4 sunglasses have a light transmission percentage of 3 to 8 percent. These are special-purpose sunglasses that should be used in certain situations, such as in the mountains where there is a need for a very high level of sun glare reduction and good UV protection. 

Are dark sunglasses better?

The dark category of the lens is more about comfort to the eyes when you are outside than protection from the harmful UV rays. While the level of darkness is important to how you see the world, and the protection it provides from sun glare, it doesn’t offer UV protection. 

UV damage should be something that you take seriously when it comes to your eyes, just as you do for your skin. 

So while darker lenses aren’t necessarily better without having UV protection they do offer you some additional benefits. For example, people who like to conceal their eyes, or make a fashion statement. 

But in order to keep your eyes healthy choose UV-protected sunglasses with a dark or gray colored tint with category 3 of darkness. Then make sure it has UV 400 rated protection. This will be an optimal choice for both comfort and protection.

Category 4 polarized sunglasses are going to be extremely dark and would be used for extreme sun conditions where there's a high glare or intense sunlight. Which makes them perfect for activities such as skiing, mountain climbing, high-altitude hiking, and desert trekking. 

What is the best light transmission for sunglasses?

If you’ve been wondering what does light transmission mean for sunglasses it is easier to understand when you understand what it is exactly. 

Visible Light Transmission or VLT is the amount of light that reaches your eyes through your lenses. This is measured as a percentage and the color, thickness of your lens, and the material it is made of affect the amount of light that will reach your eye.

There are some guidelines when choosing sunglasses that are based on VLT percentages. Knowing the purpose of your sunglasses and the conditions you’ll be wearing them most often, will help you to choose the right VLT percentage. 

0–19% VLT: These are ideal for bright, sunny conditions.

20–40% VLT: Perfect for all-purpose use.

40+% VLT: These are best for overcast and low-light conditions.

80–90+% VLT: These are basically clear lenses that are good for very dim light and night conditions.

How dark can prescription sunglasses be?

There are some important things to take into consideration when choosing how dark you want your prescription sunglasses to be. Most optical shops will tint your lenses as an option when you order your glasses. But the level of darkness and the color tint will often depend on your vision and any eye conditions that you may have. There are many instances when your eye doctor recommends a certain tint for you due to your eye health. 

Tinted lenses have been known to help reduce the pain and other symptoms associated with light sensitivity and migraine. The choice of color provides relief and protection when playing video games, long hours on the computer, or in low light situations. Discussing issues and lifestyles with your eye doctor will help to find the best tint color for your eye issues if any. 

Light sensitivity is a medical condition called photophobia. The light causes pain and certain tints will help you get the relief that you need. This has proven to be helpful in many situations.

If you suffer from migraines there are specific types of tinted lenses that can provide you some relief. It works by filtering out certain types of lights that trigger pain and prevents migraines from happening. 

When looking for sunglasses, deciding on the darkness level should be determined by the activity that you will be performing when wearing them. Your driving sunglasses won’t be the same as your fishing glasses. And you definitely wouldn’t wear your lightly tinted sunglasses for a day out on the beach when the sun is at its strongest.

At ShadyVEU we have plenty of options for you to choose from. Finding the perfect pair of shades for the day out on the boat, or an all-purpose pair of sunglasses has never been easier.


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