A lot depends on the intensity and duration of exposure. Looking at a single (or multiple) modern (superbright) LEDs up close can cause vision damage and that damage risk isn't limited to just blue LEDs. Blue is the worst because those wavelengths do the most cell damage (pack more energy). LED "blue" is not quite as bad as UV but it's close to that range and quite a few white LEDs use a blue source to "pump" a phosphor to get the rest of the spectrum so they can also pose a risk. If an area is illuminated by blue LEDs (lighting effects), long term exposure
could pose a risk. One thing which adds to the issue is that our eyes are much less sensitive to blue so it takes more blue light to light an area so people can see which results in higher intensities as far as area lighting is concerned. However blue area lighting is the exception and is not that common.
It's not so bad when the light is distributed as it is in an EVF (used as a backlight), or as it is in a common LED light bulb (diffused). The point intensity really falls off so it's not like looking at a concentrated source (like a single LED). You routinely look at blue light reflected from everyday objects (in the sun) which is just as intense or considerably more so. Of course if you spend a lot of time outdoors, you wear sunglasses (we hope) which absorb a good deal of that, particularly the UV. The same is true for EVFs. If you spend days looking at one, maybe you might be at risk, but for the casual use which is short term, the risk is low. Most flat screen TVs are one-third blue so we could be in a real fix if the risk was high.
It's just wise not to look at any concentrated LED source, particularly single LEDs (e.g., LED flashlights and the sort). The closer, the more risk but LED lighting (and its use in displays) is another story so don't start wearing your sunglasses in the house or when using your EVF