Prescription sunglasses: the quest for the perfect tint

Guide dog Zodiac with sunglasses

11 January 2019
Source: Visualise Training and Consultancy

By Daniel Williams, Visualise Training and Consultancy

I recently decided to escape the British winter – and hopefully a Siberian blast – for the sunshine of Gran Canaria. Though a last minute decision, I considered myself fairly well set for a couple of weeks of rest and relaxation on foreign shores. After all, I’d packed my budgie smugglers, a garishly coloured beach towel I’d use to reserve my poolside sun lounger, some factor 80 sunscreen and – even if I say so myself – a pretty stylish pair of shades.

Form meets function

For me, sunglasses aren’t just about looking the part. I mean I’m as vain as the next chap when it comes to wanting to looking street-wise cool, but because I’m registered blind it’s more important my shades maximise my minimal vision. There is a limit to how stylish you can look falling into a hotel pool you hadn’t noticed was there.

My particular visual impairment is called retinitis pigmentosa, which impacts depth perception and causes night blindness and issues with extreme glare. It also reduces peripheral vision, acuity and colour contrast, so pretty much everything, in short, gets reduced.

Now that’s a fair list of visual impairments for any one pair of sunglasses to cope with, but having done all the necessary research I was confident mine were up to the task. I’d been to my local low vision centre, taken their advice, had even taken my adapted sunglasses for a quick spin around my local store, and felt I had the best pair for the job.

Optimum customisation

These sunglasses had not only been fitted with my lens prescription, but had also been polarised and tinted. What’s more, the coloured tint I had been recommended represented the optimum colouration for my condition. They looked on fleek too. Which, if you’re not quite as ‘street’ as I am, translates as pretty damn cool! Big, sporty wraparounds which I thought James Bond would have been proud to wear, and Q would have struggled to better. My only reservation was how far I could truly gauge their effectiveness for two weeks in the Gran Can sun by walking around a low vision centre. Here goes….

Gran Can Carry-On

My Gran Can experience went something like this: in even sunlight my shades were absolutely fine, and I had no problems whatsoever. Whenever I walked through large areas of shade though – a grove of trees for example – I would have to take them off to have any chance of seeing where I was going and bumping head-on with a tree is more Mr Bean than James Bond. They simply didn’t adapt sufficiently or quickly enough to extreme changes in light. Then I’d walk back into direct sunlight and have to shield my eyes with my hands until I could put my sunglasses back on. After just a few minutes of this – shade off, bright light on, shade off, bright light on – I started to feel like a nodding dog, and probably looked like one too.

This wasn’t the only issue with my state of the art shades. When the sun was low they struggled to cope with the extreme glare, so off they would have to come again, and up would go my hand to protect my eyes. Even indoors I had problems. My depth perception difficulties meant going up and down stairs in my glasses started to feel like a game of Russian roulette, and off the sunglasses would come again! Up, down. On, off. Blinkin’ mad.

And the moral is…

In short, it’s probably fair to say I learned on my holiday there is no perfect pair of sunglasses for every light condition. I’m sure fully sighted people would tell you the same. The important thing when choosing and adapting your sunglasses is to think about the most common lighting conditions you will face, and make sure they are suitable for those. Also, to think about your particular visual challenges and what optical features can most ameliorate those.

All too often however I talk to people with visual impairments who are being poorly advised, or not advised at all, on the benefits of polarisation and tinting when it comes to choosing sunglasses. Professional advice is vital here because these simple adaptions can make a huge difference. For all my holiday frustrations, I’m sure that had my sunglasses not been adapted to include these features my Gran Can experience would have been a lot more problematic and a lot less fun than it actually was. And at least while everyone was shivering in Britain, I could feel the heat.

Hints for tints

With this in mind, here’s a short guide for choosing adapted sunglasses that get the job done.

  • Firstly, get fitted. Well-fitted sunglasses should rest close to your face and protect eyes from light entering from different directions.
  • Make sure your sunglasses offer UVA and UVB protection, and conform to European standards.
  • Try out a range of lens tints to find out which give you the best all around vision. You should be able to try these at your local RNIB Resource Centre or low vision service. Also, your local optician will be able to make filter lenses up to your prescription. However, if your trying sun glasses out it’s important to try them in the sun to get the maximum benefit.
  • There is a vast range of filters: within each colour range, for example yellow, there may be twenty variations, each with a slightly different impact.
  • Yellow filters generally enhance contrast, and can be particularly effective in improving vision for people suffering from conditions such as macular degeneration and optic atrophy. Orange lenses are more effective for people with conditions such as glaucoma, cataracts, and retinopathia pigmentosa. Plum-coloured filters, meanwhile, are more general-purpose absorptive filters, and are effective in helping with many of the above conditions, as well as photophobia and diabetic retinopathy.

So in conclusion

Although there may be no perfect sunglass solution for every light condition and every visual impairment, well-chosen sunglasses with the correct filter can go a long way to optimising the sight of people with low vision. They also help to ensure you only end up crashing into the hotel pool when you feel like a swim. Remember not all people with visual impairments need DARK glasses.

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