Second, even without glare they selectively reduce other reflections from objects above water, including clouds and even the sky (the reflected sky gives most of its blue color to the sea). Finally, light coming from under water is slightly polarized in the vertical plane (polarized on transmission).
1 Alzheimer's is the sixth leading cause of death in the United States. 2  Those with Alzheimer's live an average of eight years after their symptoms become noticeable to others, but survival can range from four to 20 years, depending on age and other health conditions.
About 10% of people develop the disease at some point in their lives. It becomes more common with age. About 3% of people between the ages of 65â74 have dementia, 19% between 75 and 84 and nearly half of those over 85 years of age. In 2013 dementia resulted in about 1.7 million deaths up from 0.8 million in 1990. As more people are living longer, dementia is becoming more common in the population as a whole.