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.
A specific form of closed-angle glaucoma called acute glaucoma progresses rapidly, and produces symptoms of severe eye pain, headache, blurred vision, nausea, vomiting, and halos. If not treated within hours, acute closed-angle glaucoma can result in permanent vision loss.