The Tropic of Cancer and The Tropic of Capricorn. The Tropic of Cancer and the Tropic of Capricorn each lie at 23.5 degrees latitude. The Tropic of Cancer is located at 23.5Â° North of the equator and runs through Mexico, the Bahamas, Egypt, Saudi Arabia, India, and southern China.
Dr. Elliot Werner: Neither. Halos indicate something in the transparent structures of the eye that is interfering with the transmission of light back to the retina. The most common causes of halos are corneal edema (swelling), cataract, and high humidity in the air.
Also in the list of causative agents to the dark rings around the eyes phenomenon are medical conditions and allergies which lead to itching around the eyes. As you probably already know one of the first reactions to an itch around the eye region is to rub the eye as hard as possible.