How our spectrometer promotes safe driving

If there’s one accessory that’s a must-have for driving in the summer sunshine, it’s a pair of sunglasses.

But not all sunglasses are created equal. Some do a better job of blocking bright light than others, and some are so good at it that they’re too dark to drive safely in. Did you know you might be breaking the law and liable for a penalty if you’re driving with the incorrect sunglasses?

Read on to find out how we can help by using a spectrometer to analyse your sunglass lenses to ensure they’re suitable for the road.

What is a spectrometer?

It might sound like something out of Star Wars, but a spectrometer is a state-of-the-art optical diagnostic tool.

It analyses the absorption of visible and invisible light in the UV spectrum and measures the properties of light, determining the intensity or brightness of reflected light.

How do we use it?

At Optix, we use our spectrometer to ensure your sunglasses are suitable for driving. We measure the amount of UV light that passes through and is absorbed by your sunglasses’ lenses. With accurate measurements, we can determine your sunglasses’ tint category to check whether they fall into the correct one to drive legally in.

The sunglasses tint category

sunglasses tint category

Sunglasses lenses come in 5 tint categories, from 0 to 4 that we need to take into consideration regarding sunglasses and driving. The higher the number, the darker the lens. Darker lenses absorb more light, meaning they let less light pass through them and into your eyes.

The lowest category lenses might not provide enough protection to your eyes in bright sunshine, and the highest categories are so dark you won’t be able to see clearly enough, especially if you hit a shady spot in the road.

The 5 categories are broken down as follows:

  1. Light tint (Category 0) – Absorb 20-57% of visible light. They’re not recommended for driving as they don’t provide sufficient protection from glare and bright sunlight.
  2. Medium tint (Category 1) – Absorb 58-80% of visible light. They are generally safe for driving during most daylight conditions.
  3. Dark tint (Category 2) – Absorb 81-92% of visible light. They’re great for driving in bright sunshine and during the day, but they may not provide enough visibility in low-light conditions.
  4. Very dark tint (Category 3) – Absorb 93-97% of visible light. They’re too dark for driving because they significantly reduce visibility, even in bright sunlight.
  5. Blinding tint (Category 4) – Absorb more than 97% of visible light. They block almost all light and are not suitable for driving at all. They’re so dark they’ll severely impair visibility.

Sunglasses and driving

Sunglasses and driving

A recent report highlighted how some drivers are wearing sunglasses that are unsuitable for driving without realising it. Drivers wearing sunglasses above category 2 (the legally recommended category for daytime driving) risk being fined up to £5,000.

Opticians in the City of London – we’ve got you covered

Unsure if your sunglasses are the correct tint category for driving? Come and visit our practice so we can use our spectrometer to check whether your sunglasses are safe to drive in or not. And if they’re not, don’t worry – we’ve got a wide selection of some of the best driving sunglasses available in London!