1. The Aging Eye and Circadian light: Brief Overview Thomas Hornick MD

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3. Disruption of circadian rhythm Poor performance/fatigue (Reinberg et al, 2007, Laposky et al 2008) Weight gain(Knutson et al, 2007) Breast cancer (Stevens et al 2001) Other conditions 3

4. Eye changes with age Corneal thickening reduces light Lens opacifies, increases absorption of light, especially in shorter wavelengths Decreasing pupillary size. Decreasing ciliary contraction leads to presbyopia Loss of retinal and optic nerve cells

5. Aging and light Older adults spend much of their time in muted indoor lighting. 35 minutes/day of bright light exposure compared to approximately 58 minutes of bright light per day for middle-aged adults. (Sanchez 1993) Reduced light exposure compounded due to physiologic changes senile meiosis, cataract formation, and/or increased light absorption by the crystalline lens. (Charmin 2003) Attenuation of light exposure by more than 80% in normal older adults relative to young adults. 5

7. Turner et al Br J Ophthalmol. 2008 November; 92(11): 1439–1444 Spectral sensitivity of photopic, scotopic and circadian (melatonin suppression) photoreception 7

8. Circadian light transfer function Figueiro, et al. 2006

9. Age related losses in retinal illumination 9 Turner et al Br J Ophthalmol. 2008 November; 92(11): 1439–1444

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