I've used PC Peekers about 4 years. They eliminate neck strain when using a computer with my progressive lenses. My husband uses them with his bifocals. The first 2 pair I had I purchased for $30 each from a doctor's office, and they were worth the cost. After breaking both pair, checked Walmart.com and found them for $17.88. I broke them each in the middle while cleaning the lenses. I figured out that if you hold on to he tab next to the side you're cleaning, they don't break. I had previously been holding them in the center between the lenses, and the pressure from cleaning caused them to snap in the center. The Walmart pair has not broken. I also have drilled a small hole in the tabs or just tied a ribbon around the small end of the tabs so i can hang them around my neck. The colored string or ribbon makes them easy to find if I happen to lay them down. Will not use a computer without them!