The FL-41 filter lenses in these acunis eyeshields were developed for use by people with extreme light sensitivity (photo-phobia), such as those suffering from migraine or severe traumatic brain injury.
Wearing eyeshields with these FL-41 filters can also lead to significant improvements in the frequency and the strength of eyelid closure in cases of blepharospasm (eyelid spasm) caused by light sensitivity.
A study conducted in Birmingham in the 1990s showed that wearing FL-41 filter lenses resulted in a significant reduction in the frequency and severity of migraine attacks.
Concentrating the filtering effect on a restricted wavelength range prevents the eyes adapting to ambient light conditions. This means that when the glasses are taken off, particularly indoors, the eyes are considerably less dazzled than would be the case with normal sunglasses which dim the entire visible spectrum evenly.
How do these filters work?
The retinal ganglion cells which are the main conductors of the eye’s (non-image forming) light regulation to the brain are also responsible for photophobia, which is often associated with migraine, among other things. Their sensitivity maximum is at approximately 484nm.
The pink-coloured FL-41 lenses have been specially developed for use in cases of hypersensitivity to light stimuli and specifically reduce the transmission of the blue-green wavelength range (480nm to 520nm) – the range to which migraine patients also react particularly sensitively, or which is perceived as particularly unpleasant in migraine-related photophobia.
These eyeshields are available with a metal frame (small or large), pantoscopic (tilted) plastic frame, square plastic frame, as clip-ons, or as fitovers (small or large); and in a choice of tint: 25%, 50%, or 75%. You are currently viewing the clip-on with 25% tint.
Specification
- Fitted with a pink filter (25 per cent).
- Protect against unpleasant glare.
- Reduces transmission of the wavelength range around 484 nm, which is perceived as particularly unpleasant in cases of migraine-induced light sensitivity.
- In contrast to conventional sunglasses, your eyes adjust less to “seeing in the dark” with acunis lenses and are less dazzled when you take your glasses off.
- Protects against UVA/B.
- Light transmission level: Approximately 75%.
- Blue light absorption: Approximately 30%.
- Can be used when driving according to DIN EN ISO 12312--1. Not suitable for night driving.
- Supplied with case.
Measurements
- Across the front of the eyeshield, the width of the frame is 13.1cm (5.16 inches).
- Lens frame height is 6cm (2.36 inches).
For more details about this product, check the product instructions manual (in the User Guides tab) to help you decide if this product is suitable for you.
Special order
We work with partners to deliver products on our behalf. We will pass on your contact information to be able to deliver the product effectively. While delivery is usually within seven days, it may take up to six weeks.
Important – order cancellations and returns
We are unable to cancel your order once it has been placed. Should you change your mind about this special order product, you will need to accept the delivery and then contact RNIB Helpline to arrange its return; guidance on how to do this can be found in our Returns Policy.
Please retain packaging until you're sure you'd like to keep the product.
Warranty
Two-year manufacturer’s warranty.
- Filter option Filter 25%
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