Photophobia and glare the use of filter glasses Jörgen Gustafsson Optometrist, PhD For improved: Contrast Comfort Protection 1 2 Filter vs normal tint Electromagnetic radiation What we mean by filter color: A specific part of the spectrum is absorbed Function is no. 1 priority Edge filter 3 4 1
The visible light The shorter wavelength the more energy Proportionally more energy from blue light The visible light Shorter wavelengths are refracted more Chromatic aberration Rayleigh scatter Light scatter by molecules Makes the sky blue and sunsets red 5 6 Detection in the retina Contrast Three types of cones Short ca 420-440 nm Medium ca 530-550 nm Long 560-590 nm Blue light contributes more to blur than the other colors By reduction of blue light we can increase the image quality on the retina 7 8 2
Normal contrast sensitivity? BUSER-test Normally 2 rows reduced acuity (logmar) at 10 % - VA 0,5 100% and 0,32 with 10% = normal contrast sensitivity - VA 0,5 100% with 10% only 0,13 = clearly reduced contrast sensitivity The use of test: Sometimes important just to determine reason of problems Adapting environment, lighting etc. Filter Filter does not generally improves contrast sensitivity for everyone Most people experience subjectively improved contrast Comfort 9 10 Comfort for healthy and diseased eyes Function theory by Lea Hyvärinen Blue light is causing aberrations on the retina We experience the blue light as noise Blue light absorbing filters act similar to advanced ear protection and filters out the uncomfortable noise Uncomfortable glare can be minimized without removing too much of visual information The above improves visual quality for both healthy and diseased eyes We can use brighter tints with the same glare reduction 11 Rods are more sensitivie to light than cones Rod activity is inhibited by feedback from the cones in bright light With a loss of cones in central retina the feedback is reduced This leads to uncomfortable glare Rods are more sensitive to blue light By reducing blue light the glare is also reduced With filters, we can use lighter tinted sunglasses, thus improving vision quality 12 3
Function theory by Lea Hyvärinen With the knowledge of the sensitivity of the retina: With problems from glare in AMD as much light as possible below 500 nm should be reduced Protection 13 14 UV light and blue light potentially harmful Today there is a general understanding that short wave blue light should be avoided Sometimes referred to as HEV (High Energy Visible light) Most sources defines HEV as up to 430-450 nm Blue (sun) glasses? Avoid! Increases the concentration of blue light Note! Difference between a blue coating and a blue tint Reduction of transmitted light is done by either Reflection or Absorpion Reflection can never be 100 % efficient 15 4
Natural protection in the eye From the late teens, the crystalline lens is absorbing UV light, thus protecting the retina The lens pays the price of earlier debut of cataract You should protect from UV and blue light through all stages of life Historically, there has been a problem with IOLs without UV protection Modern IOLs are available with UV and some HEV absorbance Blue light and circadian rythm Light plays a big role in our circadian rythm Blue light stimulates alertness Circadian rythm is mostly controlled by another photoreceptor with peak sensitivity at 446-477 nm (Brainard et. al. 2001) 18 The different ML Filters The different ML Filters Filter 400 C1 450 500 511 527 550 585 Description Lightly Allows parts Yellow lens Allows a small Absorbs all Absorbs all blue Red lens Dark red tinted. of the blue that part of the violet and light and parts mainly used lens mainly Absorbs light to absorbs all blue light to blue light. of the green for RP or used for some of the transmit to short wave transmit. light up to 527 Achromatopsiaopsia. achromat- light up to maintain a blue light Absorbs 95% nm. Often too 420 nm. natural color up to 450 of all light up much change in Absorbs all Absorbs all perception. nm. to 500 nm. color light up to light up to Absorbs 80% perception for 550 nm. 585 nm. of light up to healthy eyes. 450 nm. Recommendation -Comfort -Use in front of the computer -Comfort -AMD -Very good Filter Sun glasses in combination with polarization. -Contrast enhancing -AMD -Problems in N. Opticus -Sports lens -AMD -Glaucoma -Problems in N.Opticus -Very good Filter Sun glasses in combination with polarization. -AMD -Glaucoma -Problems in N.Opticus -Very good Filter Sun glasses in combination with polarization. -Glaucoma -Diabetic retinopathy -Retinitis Pigmentosa -Diabetic retinopathy -Retinitis Pigmentosa -Achromatopsia -Diabetic retinopathy -Achromatopsia 19 20 5
Lightly tinted lens that most people experience as comfortable and relaxing. Absorbs some of the light up to 420 nm To all who wants to add some comfort and protection For regular use in front of a computer ML Filter 400 Yellow lens that absorbs the short wave blue light. Increasing contrast in most circomstances. Absorbs all light under 450 nm Contrast enhancing Problems in N. Opticus Contrast enhancing sports lenses ML Filter 450 21 22 Some of the light is allowed to transmit to keep as natural color perception as possible. Absorbs approx. 80% of all light under 450 nm Very good comfort filter for most people AMD In combination with polarization high quality sunglasses ML Filter C1 Allows a small part of the blue light to transmit. Absorbs 95 % of all light under 500 nm AMD Glaucoma Problems in N. Opticus In combination with polarization high quality sunglasses ML Filter 500 23 24 6
Absorbs all blue light. Nice orange color. For most people a comfortable lens. Absorbs all light under 511 nm AMD Glaucoma Problems in N. Opticus Good looking contrast enhancing sunglasses in combination with polarization ML Filter 511 Absorbes all of the blue light and also some part of the green light. Sometimes too much change in color perception for healthy eyes. Absorbs all light under 527 nm AMD Glaucoma Diabetic retinopathy Retinitis pigmentosa Anecdotal: Fishermen ML Filter 527 25 26 Red lens mainly used for low vision patients e.g. with Retinitis Pigmentosa. Absorbs all light under 550 nm Diabetic retinopathy Retinitis pigmentosa Achromatopsia ML Filter 550 Dark red lens mainly used for achromatopsia. Absorbs all light under 585 nm Diabetic retinopathy Achromatopsia ML Filter 585 27 28 7
Most beneficial for retinal problems Summary ML Filter LLR (led light reduction) filter is available as a regular filter tint Available as a standard product ML Night Cover Night Cover HangON ML Filter LLR 29 30 FL-41 Other filter solutions Used to relieve migrane symptoms Also positive in trials for patients with head traumas Improve color perception Chromagen etc. Situation-specific solutions in many cases FL-41 Filter for migrain and ML 41 - Effective for patients with visual disturbances following different types of brain trauma. Also relieves migraines. Provides a general comfort for many. 31 32 8
Availability All filter colors can be combined with polarization The combination is high quality filter sunglasses Availability All filter colors can be combined with photochromic alternatives (exception: 585) Filter colors is available in 1.5 och 1.6 index Is an addable feature to most of our other products Large assortment of readymade products with and without polarization Cover Sunglasses Ophtalmic frames Affordable packages with powers 33 34 How to try them out Comfort is more interesting than acuity Do not assess the function on the acuity chart! Ask the patient about the experience Low contrast acuity more interesting than 100 % contrast If possible get the patient to try them at home Ultimately, filters should be tested and evaluated for an extended period of time Case Man 55 years Diagnosis; Juvenile AMD VA: 0,5 (100%) VA: 0,16 (10%) Small central scotomas Emmetropia Distance: Filter450 and Pol 1-450 Reading prescription ML Bino +3,5 + 450 filter 35 36 9
The frame Type of frame also has influence on glare and protection Ideally, a frame should control/block light from all directions Wrap around Biocover Sun Guard Special use of ML Filters 37 38 ML Night Cover ML Night Cover A special filter color that blocks the most intense blue light but lets through as much of the remaining light as possible. Always comes with an anti-reflex treatment for maximal transmission of light and reduction of disturbing reflexes. 39 40 10
AMD Comfort Night Cover HangOn ML Filter LLR Plano, -0,25 or -0,50 Without and with nosepads Powerful combination for easy-to-use solution Combination of filter and image magnification ML Filter C1 Image magnification of 3 % and 6 % 42 Blue light and bipolar disorder Interesting studies Henriksen et. al (2016) showed that blue blocking filters can be an effective treatment for persons with bipolar diagnosis 32 persons, three years Blue blocking filters reduced the length and severity of the manic state The filter used in the study had a cut-off wavelength of around 527 43 11
Study: Filter for AMD patients Langagergaard et. al. (2003): Age-related macular degeneration: filter lenses help in certain situations I this study the filters is called LVI filter (LVI was at the time distributor of Multilens products in Denmark 32 AMD patients tested ML Filter 527 and Corning 527 (mineral lens) Results: Study: Filter for AMD patients Acuity with 100 % contrast: Small improvement of ML Filter 527 (p=0,14) Small deterioration of Corning 527 (p=0,09) Acuity with 10 % contrast: Significant improvement of ML Filter 527 (p=0,03) Very small improvement of Corning 527 (p=0,79) 45 46 Results: Study: Filter for AMD patients Acuity with 100 % contrast: Small improvement of ML Filter 527 (p=0,14) Small deterioration of Corning 527 (p=0,09) Acuity with 10 % contrast: Significant improvement of ML Filter 527 (p=0,03) Very small improvement of Corning 527 (p=0,79) HangOn New innovative frame - Easy to use over most normal glasses Sustainable, light and allergy-friendly 47 12
HangOn, HangOn NP, HorizOn with filter update Innovative HangOn allows filter usage freedom Our family with HangOn frames is now available with filter The following filters are available: ML 41, ML 400, ML C1, ML 450, ML 500, ML 511, ML 527, ML 550, ML 585 ML Pol 1, ML Pol1/400, ML Pol1/C1, ML Pol1/450, ML Pol1/500, ML Pol1/511, ML Pol1/527, ML Pol1/550, ML Pol1/585 ML Sight Optimizer are available in 4 powers +1.0, +1,5 +2.0, +3.0 Labelled: 10, 15, 20, 30 ML Pol 3, ML Pol3/400, ML Pol3/C1, ML Pol3/450, ML Pol3/500, ML Pol3/511, ML Pol3/527, ML Pol3/550, ML Pol3/585 Multilens Phone: +46 31 887550 E-mail: info@multilens.se support@multilens.se www.multilens.com www.mlfilter.com www.multilens.se 51 13