When i get my eyes checked every year, if i forget to mention it the optometrist, they always comment on the brownish stain in my eye and damage to it. The doc had removed 2 bits big enough to see with the naked eye, (He gave them to me on a card as a souvenir / reminder to wear better safety gear in the future.) but a smaller microscopic bit was left in for a few days until discovered and now i've got a "rusty eye". At the time i was wearing safety glasses. Now i always try to remember to wear my welding helmet or full faceshield.