When it comes to eyewear, the small details really matter over time. Some charts are very generic and do not match real measurements at all. Loose hinges make the glasses slide down the nose again and again. I also pay attention to return policy and customer service response time.
If anyone is interested in real user experiences, I sometimes write short notes about the shops I test.
You can find one of the pages here:
check this link
(https://knowledgecom.izeberg.com/blog/index.php?entryid=50794)
Reading comments with real body photos is one of the best ways to check sizing. Now I try to read as many real user reviews as possible before I buy anything. When a store shows clear shoulder width, bust, waist and length, it is much easier to choose. I also check if the lenses have any blue light filter or anti-reflection coating. For things that I use every day, I prefer to pay a bit more if the quality is stable.
Just sharing my personal feedback.