Magnesium nitrate in eye?!

Usually, if you get something in your eye that is at all irritating, you will know it, as it is really painful. The toxicity of magnesium nitrate is pretty low, it is weakly acidic in solution, not sure if it would cause damage or not. Probably if you were going to go blind or something it would have already happened by now. Generally, it is best to wash out your eyes immediately if anything that might cause damage got in them. Also, if handing chemicals & other stuff that might splash in your eyes and cause a problem, maybe get some safety glasses.