A teenage girl presented to the hospital emergency department with a three-week history of intermittent frontal headache, which was worse in the morning and associated with nausea, vomiting, lethargy, ...

Lack of pain Ischemic optic neuropathy, NMO-associated optic neuritis, LHON, Susac syndrome, various maculopathies Disc hemorrhages Ischemic optic neuropathy, inflammatory optic neuritis ...

The phase and the group velocity of light propagating in conventional optical media cannot exceed the speed of light in vacuum. However, in so-called epsilon-near-zero (ENZ) materials, light ...