Physiological Mechanisms of the Effects of Yellow Lenses

1. Physiological Mechanisms of the Effects of Yellow Lenses David Glabe, MS OD candidate Jim Sheedy, O.D., PhD

2. Observations of Yellow Lenses • Subjective Attributes • Increased brightness perception • Increased ability to see objects against background • Increased overall clarity of vision • Increased patient comfort during eye exam • Decreased glare

3. Who uses yellow lenses? • Marksmen • Bikers • Skiiers/snowboarders • Pilots • Hunters • Drivers • AMD sufferers • Post-surgical cataract patients • Optometrists/ophthalmologists • Northwesterners (think overcast skies) • Computer users (ex. Gunnar Optiks)

4. What does the literature say? • Visual acuity and AC/A - no significant effect (Wolffsohn et al. 2000) • Contrast sensitivity – ?? • Chromatic aberration – decreases by more than 1/3 … in fish (Sivak et al. 1978) • Selectively decreases blue-light damage to RPE cells (Tanito et al. 2006) • Brightness – up to 40% increase (Kelly 1990) • Discomfort glare – significant decrease (UMTRI) • Subjective preference in glare conditions – Yes! (Wolffsohn et al. 2000)

5. But, how? • Multiple theories, no consensus • Glare reduction • Possible rod involvement (Vos 2003) • S-cone inhibition • Pupillary response (Chung and Pease 1993) • Circadian receptor response (Kooi and Alferdink 2004) • Brightness perception • May be rod-mediated (Kelly 1990) • Psychological association with sun (Wright 1949) • Pupillary diameter (Chung and Pease 1993) • Opponent pathways, chromatic channels (Luque et al. 2006)

6. An intriguing study… • Kooi and Alferdinck, TNO Human Factors 2004 • Attempt to resolve confusion on mechanism behind discomfort glare reduction observed with yellow lenses • Rods • S-cones • Melanopsin • Pupil

7. Kooi and Alferdinck, 2004

8. Kooi and Alferdinck, 2004 • Method of adjustment procedure – match the brightness level

9. Kooi and Alferdinck, 2004

10. S-cone spectral sensitivity S-cone M-cone L-cone

11. Sivak et al, 2005 • Measurement of discomfort glare from various types of headlamps • Blue-cone weighted power highly correlated with discomfort glare

12. S-cones and brightness • S-cones may play a key role in brightness-enhancing effects of yellow lenses as well • Experimental design in process to test this hypothesis

13. Where the rubber meets the road • Is it possible to design an “ideal” yellow ophthalmic lens? • Can an algorithm be created to predict effects on brightness and discomfort glare? • Potential utility in many fields – vision ergonomics, aviation, athletics, medicine, driving

14. References • Chung, S. T., & Pease, P. L. (1999). Effect of yellow filters on pupil size. Optometry and vision science , 59-62. • Kelly, S. A. (1990). Effect of yellow-tinted lenses on brightness. J. Opt. Soc. Am. A , 1905-1911. • Kooi, F., & Alferdinck, J. (2004). Yellow lessens discomfort glare: physiological mechanism(s). Soesterburg, The Netherlands: TNO Human Factors. • Luque, M., Capilla, P., Diez, M., & Felipe, A. (2006). Effect of a yellow filter on brightness evaluated by assymetric matching: measurements and predictions. J. Opt. A: Pure Appl. Opt. , 398-408. • Luque, M., P, C., MA, D., & A, F. (2006). Effect of a yellow filter on brightness evaluated by assymetric matching: measurements and predictions. J. Opt. A: Pure Appl. Opt , 398-408. • Sivak, J., & Bobier, W. (1978). Effect of a yellow ocular filter on chromatic aberration: the fish eye as an example. Am J Optom Physiol Opt , 813-817. • Sivak, M., Schoettle, B., Minoda, T., & Flannagan, M. J. (2005). Blue content of LED headlamps and discomfort glare (UMTRI-2005-2). Ann Arbor, Michigan: The University of Michigan Transportation Research Institute. • Stockman, A., & Sharpe, L. (2000). The spectral sensitivities of the middle- and long-wavelength-sensitive cones derived from measurements in observers of known genotype. Vision Research , 1711-1737. • Stockman, A., Sharpe, L., & Fach, C. (1999). The spectral sensitivity of the human short-wavelength sensitive cones derived from thresholds and color matches. Vision Research , 2901-2927. • Tanito, M., Sachiko, K., & Anderson, R. E. (2006). Protective effects of soft acrylic yellow filter against blue light-induced retinal damage in rats. Experimental Eye Research , 1493-1504. • Vos J.J. (2003). Reflections on glare. Lighting Res. Technol. 35 (2), 163-176. • Wolffsohn, J. e. (2000). Contrast is enhanced by yellow lenses because of selective reduction of short-wavelength light. Optometry and Vision Science , 73-81. • Wright, W. (1949). Photometry and the Eye. London: Hatton Press.

15. Thank you!

16. Rods and cones • 120 million rods • 6-7 million cones • "red" cones (64%), • "green" cones (32%), • "blue" cones (2%) • green and red cones are concentrated in the fovea centralis • blue cones have the highest sensitivity and are mostly found outside the fovea

17. Triplicity of Vision • Rod system • S cone system • Earliest cone system • R/G cone system • Newest cone system

18. Young-Helmholtz color theory • Trichromatic vision http://images.google.com/imgres?imgurl=http://www.diycalculator.com/imgs/cvision-how-works-01.jpg&imgrefurl=http://www.diycalculator.com/sp-cvision.shtml&usg=__bcKsdqqMJq21AcPwXRe14cOmeE4=&h=356&w=505&sz=44&hl=en&start=16&sig2=G-xn-igItpoeGkLmeS3uBQ&um=1&tbnid=ofx71CnhO3LJuM:&tbnh=92&tbnw=130&prev=/images%3Fq%3Dcolor%2Bvision%2Btrichromatic%26hl%3Den%26sa%3DN%26um%3D1&ei=bCzVSbD9J5iQswP3pIGgCg

19. Hering Color Theory • color opponency http://images.google.com/imgres?imgurl=http://www.webexhibits.org/colorart/i/Hering.jpg&imgrefurl=http://www.webexhibits.org/colorart/color.html&usg=__5TSvOfaF7kre5QsLnzXcGu0mRr4=&h=97&w=80&sz=3&hl=en&start=11&sig2=4lK2UCnnQPftLx5InDElzw&um=1&tbnid=oP0ICq-prkaoGM:&tbnh=81&tbnw=67&prev=/images%3Fq%3DHering%2Btheory%2Bcolor%2Bvision%26hl%3Den%26sa%3DG%26um%3D1&ei=7C3VSbmrOqectAOPudyyCg

20. They are both right • The difference? • Y-H moves from physical stimulus to perception • Hering looks at color from the perceptual side

21. Putting the 2 together • It’s blue vs. red/green Ganglion cells Cones