I've worn Lennon sunglasses exclusively my whole life. The last legit pair I bought in the 1990's and have never been able to find the correct size and shape frames since. I scoured the internet for a pair to install progressive lenses into without luck. My brother in law found this pair and referred me...what a pleasant surprise! The diameter is almost exactly as small, and the shape is almost perfectly round, it's as close as it gets folks; these are a fantastic pair of glasses, as close as you will get to the old Lennon design, the titanium frame and nosepiece are great looking. I had my progressive lenses made and fitted into these frames, I just received them back the other day. I couldn't be happier! I'll be ordering more for new sunglasses and spare opticals. Thank you!