These are genuine 3M brand. They are not cheap junk. They are very optically clear and are easy to wear when you are working. I use them with my machine tools and even working under the car to keep dirt out of my eyes.
My father used these glasses at his company for safety. To save money, he purchased them in large quantities (500 at a time). I kept what I wanted (a lifetime supply for me) out of his stuff and how I am going to sell 10 pairs for $30.00.
If you buy them at Home Depot, you will pay $26.47 plus tax for a pack of 4 glasses. Getting 10 for $30.00 is a much better deal. Having 10 pairs is a nice number to have at various places in your home shop. I am down to the last batch of 10 that I want to sell as I am keeping the rest that I have.