"The results of this testing (explained below in further detail) show significant health risks from some of Cree LED’s visible light LED components when viewed without diffusers or secondary optical devices. These risks warrant an advisory notice to indicate the potential for eye injury caused by prolonged viewing of blue light from these devices."

* https://cree-led.com/media/documents/XLamp_EyeSafety.pdf

No, if you didn't watch the video I'll tl;Dr it.

Phosphors glow when they're lit with UV light. LEDs don't make a lot of UV light but it's significant enough for art studios to change to these high CRI LEDs so that the UV doesn't cause it damage over time.