What is light transmittance in sunglasses?

Sunglasses are not only a fashionable accessory, but also important protection for our eyes against harmful UV radiation. When choosing the right model, an important aspect is the ability to transmit light, i.e. the amount of light that passes through the lenses of the glasses. In this article, we will discuss what the light transmittance of sunglasses is and why it is important.

The ability to transmit light ( VLT - Visible Light Transmission) is the percentage of the total amount of light that passes through the lenses of sunglasses. The higher the value, the more light passes through the lenses, which can be beneficial in dimly lit areas. However, the lower the value, the less light penetrates the lenses, which is beneficial in brightly lit places.

When choosing sunglasses, it is important to select the appropriate light transmittance value for the conditions in which the glasses will be worn. A value that is too low may cause your vision to be too dark and make it difficult to see details in dimly lit areas, while a value that is too high may cause glare and poor color reading in brightly lit areas.

It is also worth paying attention to the fact that different sunglasses filters have different ability to transmit light. For example, polarizing filters may have a lower light transmittance value because their purpose is to reduce glare and increase contrast.

In the case of Polaroid sunglasses, we can find glasses with the following categories:

Cat. 0 – clear or very light tint -
(transmits 80-100% of light)
The lens is completely transparent or slightly smoked. This lens can be found most often as the second or third lens in sports glasses. It is perfect for cyclists during evening riding.

Cat. 1 – light tint - (transmits 43-80% of light)
The juices are slightly darkened - often yellow or amber. They work well in poorer light conditions.

Cat. 2 – medium
- (transmits 18-43% of light)
Medium darkening lenses work well on days with low sunlight intensity

Cat. 3 – dar k - (transmits 8-18% of light)
The most common obfuscation filter category. The most universal, perfect for everyday use on sunny days and during holidays in hot countries.

Cat. 4 – very dark
- (3-8% of light transmits)
Lenses with very strong darkening. Polaroid does not recommend them for driving due to the very strong darkness. They are used in very bright sunlight, e.g. by mountaineers in snow-covered mountains.

To sum up, the ability to transmit light ( VLT - Visible Light Transmission) is an important aspect to consider when choosing sunglasses. It is important to choose the appropriate value for the conditions in which we will wear glasses to ensure comfort and optimal vision. Ultimately, the choice of filter depends on the user's individual needs and preferences.