I have the same problem and as far as i can tell its allergies for me. The only time my eyes are not red are when I am experiencing no other allergy symptoms. Washing my eyes out regularly helps a bunch and often provides an almost instant feeling of relief.
Those product links seem interesting for liver support. I hope its not a liver indication :( My eyes have a barely noticable line thru the center of yellow tint but since its always right were the redness is worst I figured (hoped) it was just that.