That complicated "slot and channel" into the eye of the side threading needle cannot be stamped like a traditional eye. It has to be cut in small batches to keep the integrity of the geometry. The area where this thread is resting is called the stop bump. It locks the thread inside of the eye. (Video to come)
Spiral Eye needles cannot be manufactured like traditional eyed needles. The slot and channel must be cut into the eye.
A family run small business in Minnesota, Unity Tool Inc. makes Pam's Spiral Eye Needles
Spiral Eye needles are made in small batches to keep tight tolerances on the geometry.
When "fixiing" the needle, Pam wanted to fix everything. Generally sewing neeedles are made from Nickel plated steel. Unfortunately alot of women in particualr are allergice to Nickel . Their fingersitch and sometimes peel and their eyes get red when they sew because they touch their eyes after working with the nickel plated steel.
Featured a second time in the US Patant Office newsletter, The Inventor's Eye in June 2014 in John Calvert's last article titled "Patents of my Career" https://www.uspto.gov/learning-and-resources/newsletter/inventors-eye/patents-my-career-0