I "was" a long time Zeni Optical customer. I ordered a second pair of progressive glasses that I used as back-ups for traveling. I recently took the glasses to my ophthalmologist after having some eye issues. They evaluated the glasses and found the coating was defective. (I have pictures).
I contacted Zenni and sent them the pictures. They provided a lame excuse that the distortion was from "heat." This is a laughable excuse. I have multiple pairs of Zenni glasses (and others) and they have never had this flaw. They basically told me I could buy another pair if I was unhappy.
Obviously, I will no longer order glasses from them. I have glasses from several manufacturers and I have never seen distortion and flaws in the lenses—or had such poor customer service concerning something as important as vision.
Recommendation: Avoid them