Symptoms can be serious, and the disease can be fatal â especially for babies, the elderly, and people with weakened immune systems. When influenza pandemics occur, they spread quickly, often killing large numbers of previously healthy people. From 1918 to 1919, a flu pandemic hit the U.S. in three waves.
Enucleation (Eyeball Removal). Enucleation is the removal of an eye. It is an irreversible method of treating various disorders of the eye. Reasons for enucleation include: 1  Severe untreatable trauma, such as a perforated or ruptured eyeball. 2  Uncontrollable glaucoma.
A vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision. When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the projection of the image is in the centre of the retina in both eyes.ergence movements are closely connected to accommodation of the eye. Under normal conditions, changing the focus of the eyes to look at an object at a different distance will automatically cause vergence and accommodation, sometimes known as the accommodation-convergence reflex.