Eye damage is cumulative, so not seeing any black dots in vision or distortions on an amsler grid is is good, but is no indication that you haven't actually suffered some damage.
We also have a huge blindspot in each of our eyes, which if hit, but not seriously damaged, may not show any symptoms, and our brains are superb at masking visual aberrations. Please do not take your eyesight for granted, and be VERY careful of any shiny/smooth surface, including water and windows.
Looking at a dot on a matte dark surface is generally safe, but as other have mentioned, we can't really see 405nm well, so even though you have the laser focused, you may still be seeing more of a blob, vs a nice dot as you'd get from 650nm, or 532nm lasers.
Quite dangerous, kinda like IR but not as bad.
IR lasers can be very dangerous with no visible light at all, or just a dim glow, near the visible spectrum, and the same is true of lasers below ~350nm.
Generally the only time people here run into IR is with green lasers, and no IR filters. In that situation, the leaking IR is actually far far less dangerous than even a relatively low power 405nm, since it diverges so quickly, and is not absorbed as easily.