The only school i was interested in that required of a letter of rec from an optometrist was Nova, and i thought it was strange to have such a requirement. Yes, you should get experience by shadowing an optometrist. You shadow as long as you want and at as many different places as you want. It's not that big of a deal. It's more for you to find out whether or not optometry is for you. I simply called up a local private optometrist and asked her if I could shadow her for a day and she was fine with it. I got something out of it, and it was only for a day. Shadowing for 40 hrs is a little extreme I think, but it just depends on what works for you. Yes, if you work for an optometrist's office, it will look good on your application. Is it required? No. I only had one day of shadowing and never worked in an office and was accepted. Quite a few of my fellow students worked in offices but many others like myself, haven't. Hope this helps!