Originally Posted by ItsJustMe

It's not the daylight conditions that concern me. In full bright daylight, I'm happy to have my 600 lumen strobe, wouldn't want less.

The problem is in rainy conditions, it can be pretty dark, and windshields are wet and a 600 lumen strobe might be pretty distracting.

Originally Posted by Athens80

I did that today, with a 400 lumen light. It's very noticeable, particularly straight on axis from five feet. It didn't blind me. It didn't leave me with spots in my vision for any minutes. When your eyes are adjusted to daylight, cycling lights just aren't that bright. My vision was and is fine.

You seem to recall someone writing that drivers were disturbed by someone's blinking light. If you find that writing and find that they were writing about a situation in broad daylight, then I think you've found a logical fallacy. The fact that drivers speed, text, run red lights, weave, or stop in the middle of the street in broad daylight has nothing to do with cycling lights. Many drivers drive poorly, and most of the time your behavior did not cause them to drive poorly.

Yes, flashing modes can be too much at night or even at dusk, when the ambient light is orders of magnitude less than in full daylight. I'm talking about use of cycling lights in full daylight.

I'm dealing with real life, where I've seen cyclists with Niteriders and Cygolites and Lezynes and Magicshines flashing away in broad daylight, and they're noticeable but not anywhere near blinding or dangerous. And I'm dealing with real life applications of cycling lights. Holding a light right in front of your eyeball and saying that it's too bright to be comfortable has zero to do with cycling applications.