Sunglasses classified in different categories from 0-4.

The higher the number is, the darker the lens are.

Choosing one is personal preferences, for both Aniridian or non-Aniridian.

One of the main factor is base on your light sensitivity level.

The more light sensitive you are, the darker lens would suit better for you as it cut down the glare more.

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How about for Aniridia babies?

How to choose the right one for them?

Obviously they can't express themselves yet.

For me, I have two pairs for my little one, Cat. 3 and Cat. 4.

Cat. 4 I will use it for the bright sunny days.

Cat. 3 I will use it for a bit cloudy, shaded places.

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Parents! TRY IT ON!

One of the tips I found very useful is, try it on yourself (parents!) - Don't worry it won't break, they are usually made for unbreakable!

I will wear it on my own and look up to the ceiling lights/outdoor sky to get the feel of it. That is the moment I know which glasses is the best to cut out the glare and feel most comfortable with :)

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Category 0
Cat 0 lenses are either clear or have a very light tint, they are used for safety glasses or spectacles where you need to see clearly what you are doing.

Category 1 - suitable for fashion
Cat 1 lenses are for casual use, used as a comfort filter in cosmetic and fashion eyewear.

Category 2 - suitable for general purpose, watching and taking part in sport
Cat 2 lenses are the most common category to be found in sunglasses, for general use they provide good protection from visible light and from UV rays. This lens will have a tint which allows through less light than category 1 but more light than category 3.

Category 3 - suitable for open mountain ranges
Cat 3 - Provide extra protection from both visible and UV light. These lenses will usually only allow less than 20% of visible light to penetrate the lens. This means that they will block out 80%+ of light.

Category 4 - suitable for high altitude trekking and mountaineering.
Cat 4 - Provide a high level of protection from visible and UV light. These lenses are not to be worn when driving as they are too dark. These lenses will allow less than 10% of light to transmit through the lens. They are to be used for specific situations only - not for a pair of everyday sunglasses.

Ultraviolet Light (UV) Protection - Overexposure to ultraviolet light is thought to be a cause of cataracts, retinal damage and other eye problems, so protection from UV rays is an essential function of sunglasses, all our sunglasses offer 100% UV protection, no UV light will pass through the lens.

Visible Light Transmission (VLT) - This is the measure of how much light your sunglass lens lets through to your eye and can be expressed as a percentage, therefore a VLT of 1% means very dark glasses indeed, and a VLT of 100% means all the light is getting through and the lens is therefore a 'clear lens'.

Rather than quote a percentage for each lens they are categorised as follows:

Category 0; 80-100% VLT
Category 1; 46-79% VLT
Category 2; 18-45% VLT
Category 3; 8-17% VLT
Category 4; 3-8% VLT