I have been having a lot of issues with my contact lenses such as constant itching. Thus I decided to change my lens liquid from Renu to this make/brand. It is more expensive but there is really no discernible difference otherwise. I also realised the constant itching was because I was using my eyes for over 15-17 hours a day, the digital eye strain was causing my eyes to ache, itch and go red. So while these are a little superior than RENU, essential Renu is a lot cheaper and does the same job. I would rather stick to RENU because of the slightly cheaper price. 500+ for a bottle is a lot to ask for one would think. Thankyou.