Further, African Americans did not have the freedom to choose where and how to live due to the effects of state-sponsored restrictive covenantsâlegally binding contracts making it illegal to rent, sell, or lease housing to black people (in some regions it included other nonwhites).
Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common clinical presentation of acute ischemic damage to the optic nerve.Most treatments proposed for NAION are empirical and include a wide range of agents presumed to act on thrombosis, on the blood vessels, or on the disk edema itself.onarteritic anterior ischemic optic neuropathy (NAION) is the most common clinical presentation of acute ischemic damage to the optic nerve.
NAION is estimated to affect as many as 6,000 Americans each year. The condition results from a painless swelling of the optic nerve that causes a rapid reduction in vision. Those stricken with NAION often awake one morning with vision loss, or vision loss may stutter and worsen over one to two weeks, Johnson says.Risk factors include hypertension, diabetes, a history of fever blisters and a characteristic appearance of the optic nerve that can be recognized by ophthalmologists.hose stricken with NAION often awake one morning with vision loss, or vision loss may stutter and worsen over one to two weeks, Johnson says. Risk factors include hypertension, diabetes, a history of fever blisters and a characteristic appearance of the optic nerve that can be recognized by ophthalmologists.