Primary headaches. A primary headache is caused by overactivity of or problems with pain-sensitive structures in your head. A primary headache isn't a symptom of an underlying disease. Chemical activity in your brain, the nerves or blood vessels surrounding your skull, or the muscles of your head and neck (or some combination of these factors) can play a role in primary headaches.
The first flat screen TV was invented in July 1964 by a team at the University of Illinois. ... That year, LCD screens were sold in sizes up to 42 inches.
Stereoscopic 3D television was demonstrated for the first time on August 10, 1928, by John Logie Baird in his company's premises at 133 Long Acre, London. Baird pioneered a variety of 3D television systems using electro-mechanical and cathode-ray tube techniques. The first 3D TV was produced in 1935.