The sun's spectrum is relatively smooth, whereas there are some grow lights that have a narrow, intense spike of UV designed to match chlorophyll B's absorption. Not all grow lights have this spectrum, but it's worth being careful. It's one of the reasons why some grow lights come with a warning about using eye protection.
My understanding is outside, your pupils will dilate as the light increases, protecting your retina from increased UV. If you had a strong emitter of UV in a relatively dim room, your pupils wouldn't shrink and would allow more damaging UV to hit your retinas.
I'm not sure where you got this understanding from, but the LED lights I'm talking about (grow lights) are definitely bright enough to make your pupils shrink.
> If you had a strong emitter of UV in a relatively dim room
A 150 watt LED right above your head is the opposite of dim.
They emit a pleasant looking spectrum, have good heat sinks for longevity, have high-quality ballasts, built-in dimmers and do not flicker.
They also blow out any alternative out of the water when it comes to pure brightness for precision work (soldering, painting minis, etc.)
They are also fairly cheap (can find some lights as low as 50c/watt on sale)
Oh and lastly - I can always just move them and use them to grow any kind of plants (wink wink, nudge)