Gelsemium sempervirens is evergreen. I have both the common single yellow flowered one and the double called 'Pride of Augusta'. Flowering is brief but the foliage is especially vigorous and evergreen, with some purplish tones in Winter.
You cannot see through it.
I am growing Lonicera sempervirens 'John Clayton' and one Brushwood Nurseries sells as L. magnificum. Amazingly long blooming plants but not evergreen here and a mass of tan tangle all Winter. Not unattractive, but I can see through them in Winter to the trellis underneath.