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Transmission Category (T%)
The Transmission Category indicates the percentage of visible light that passes through a lens. It is a key parameter for assessing perceived brightness, sharpness and visual comfort in different lighting conditions.
What is Transmission Category?
The Transmission Category (T%) represents the amount of light that reaches the eye after passing through the lens. It does not relate to UV protection, but solely to perceived brightness and visual performance. It is a technical value used to describe materials, treatments and tints.
- Percentage value — Indicates how much light passes through the lens.
- It depends on the material and the treatments applied — Purity, anti-reflection and colouring affect the Transmission Category.
- It affects the perception of light — It determines how light or dark the environment appears.
Why it is important
- Sharpness — A suitable Transmission Category improves image quality.
- Visual comfort — Reduces fatigue and perceptual instability.
- A luminous experience — It determines how natural the view is, both indoors and outdoors.
- Choosing lenses — Essential for selecting materials, finishes and colours.
Where it is used
At Isolani Optical Centres, Transmission Category is taken into account when selecting lenses to ensure balanced, stable and comfortable vision in all lighting conditions.
- Materials — Transparency and purity influence the Transmission Category.
- Anti-reflective coating — Increases the amount of usable light whilst reducing glare.
- Photochromic lenses — They adjust the Transmission Category according to the light.
- Sunglasses — Each colour scheme has a specific Transmission Category.
Isolani Experience
Each lens is designed with the frame, technical specifications and lifestyle in mind, to ensure an ideal balance between visual quality, comfort and light management in every environment.
Ongoing support
The ideal Transmission Category depends on your daily use and lighting conditions. At Isolani Optical Centres, we offer ongoing support with adjustments, non-medical checks and updates to your optical solutions whenever necessary.
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The information on this page is provided for information purposes only and relates to the optical and commercial sectors. It does not contain any medical, clinical or diagnostic content.