Question

Suppose that we want to determine whether or not amount of light exposure is linked to depression. We identify 5,000 participants across the United States with no intention of moving to a different permanent residence within the next two years and classify them as living in an area with high or low light exposure. We exclude those who are experiencing depression symptoms at baseline. We then follow them up for two years and determine whether they have experienced depression since baseline. There were 1500 participants residing in low-light areas and 3500 participants living in high-light areas. Of those in low-light areas, 500 participants experienced depression, and of those in high-light areas, 500 participants experienced depression. Assume the exposure is low-light. What type of study is this and which measure of association would be more useful in this case?

Answer 1

Light is used to treat seasonal affective disorder. Sensitivy to light is associated with depression. It causes depression,anxiety,pain,high blood pressure,migraine head ache and panic attack. Light at night may contribute to depresssion and suicidal thoughts and suppressing sleep signals.
Photophobia:
​ It is a symptom of abnormal intolerance to vissual perception of light..Patient may experience different type of conditions and problems and skin diseases..it can affect their optic nerve and nervous system.
​    There fore in America most of people suffer from severe and painful sensitivity to light..Over 40millions people in the US for medical reasons are very sensitive to light..especially the brightness of sun and glare..Due to this millions of people suffer from magraine head ache and depression in USA.
​ The good news is that help available for psychological and social counselling and other programs.
​ Measures:
​    Electromyography was used to measure subjects and serving a function of biological protection is useful. Sunglasses outside,of course are fine blepharospasm to wearing FL-41 sunglasses for two weeks will be useful among patients. Be sure glasses block blue-green..