I have been an Optician for 14 years. My dad was Diagnosed with Parkinson's about a year ago. After seeing all the info on Blue Glasses here, I decided to make up a pair for my Dad. So here's the technical info your optician must use exactly or the tint won't be the correct shade or intensity. TINT -- BPI BLUE (2 bottles to 1 quart of water. Must be freshly mixed!!! Tint even 2 days old will not give the appropriate results!!) LENSES-- CR39 PLASTIC (These are standard plastic lenses. You cannot use those light weight lenses -Hi Index or Polycarbonate for this tint! They will not tint properly.) TIMING--2 HOURS (It will take right at 2 hours in the tint solution for these to be dark enough to be effective.) ***They will be DARK*** INTENSITY--50 % LIGHT TRANSMISSION (These would be classified as sunglasses in the optical industry. These degree of tint **#3 Blue** is dark and may be too dark for individuals with cataracts. Hopefully your optician will be willing to work with you in acheiving the intensity you need.) The color that these will turn out to be will be quite shocking to look at to the average person. But once you put them on they are so soothing that you will wonder how you ever got by without them. If you want to see about what the color should be before you commit to this here's how: 1. Go to your PAINTBRUSH program in Windows (this assumes you have Windows). 2. Now down along the bottom you will see the color pallete default for PAINTBRUSH. 3. The color of blue on the top row is the shade you are looking for. 4. If you have a color printer and it is configured correctly you can print off an example to take with you to the optical shop. a. click on the color b. click on the tool bar, right side, the filled square. Now place your cursor in the center of your screen click and hold your left mouse button and drag it across and down about 2 inches, now release the left button. You should instantly have a square 2 x 2 filled with the appropriate blue color. c. Select print from the FILE menu (and if your printer is configured to print SCREEN MATCHED COLORS) you should have a good example of the color you need. If none of this works you can send me a self addressed envelope, with *2* first class stamps on it and I will send you a tint chip to take to your optician. TINT CHIP P.O. BOX 45994 TAFB, OK 73145 You must not vary from this specific color or the glasses will not work. Good luck!! Virginia ABO#12343