Correct lack of cohesiveness issues in the given text.
Black lights produce light in the UV range, their spectrum is mostly confined to the longwave UVA region. That is, UV radiation nearest in wavelength to visible light, with low frequency and therefore relatively low energy.
Although black lights produce light in the UV range, their spectrum is mostly confined to the longwave UVA region, that is, UV radiation nearest in wavelength to visible light, with low frequency and therefore relatively low energy.