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.
show more The human eye contains a molecule called 11-cis-retinal that changes conformation when struck with light of sufficient energy. The change in conformation triggers a series of events that results in an electrical signal being sent to the brain. The minimum energy required to change the conformation of 11-cis-retinal...