The object of convergence is the directing of the yellow spot in each eye towards the same point, so as to produce singleness of vision; diplopia, or double vision, at once resulting when the image of an object is formed on parts of the retina which do not exactly. correspond in the two eyes.
Hives are red, itchy, slightly elevated swellings. Itching may be severe. Hives have clearly defined borders and may have a pale center. Typically, crops of hives come and go. One hive may remain for several hours, then disappear, and later, another may appear elsewhere.
Sometimes, hives last for six weeks or more, a condition called chronic (or idiopathic) urticaria. Often, no cause is found for this chronic condition, and it usually goes away on its own after several weeks. Symptoms. Hives appear as wheals (swellings) on the skin, sometimes pink or red and surrounded by a red blotch. Typically round or oval, hives often itch. Hives vary in size, and some may blend to form larger areas of swelling. Hives can affect skin on any area of the body, especially the trunk, thighs, upper arms and face.