Tinting eyeglasses is an ideal project for the savvy do-it-yourselfer. With a bit of money, time, and patience, almost anyone can dye optical lenses with little preparation. The easiest lenses to tint are the uncoated CR39 lenses. This material is very porous and accepts dyes without any major problems.
Heat the tint machine and mix the solution with the dye packet. Pour the mixture into the heat machine tray. (Advanced tint machines contain up to nine colour trays.) Allow the tint machine to heat the dye.
Remove the lenses from the frame by opening the frame with a tiny screwdriver that comes with a glasses repair kit. Be careful not to strip the screws. If the lens is held in a plastic frame tightly, you may need to gently warm the frame with a blow dryer. Do not use boiling water, as the glass lens may crack. After heating the frame, gently wiggle it and push on a lens simultaneously. With either method, the lens should easily pop out. If these methods do not work and additional pressure seems to be needed, please seek assistance at a local optical store or office.
Place one lens into each lens holder, and clamp the holders around the lenses securely. Submerge the lenses into the dye; they will only take to the tint and colour if the dye is very hot. The longer the lenses are in the dye, the darker and more intense the colour will become. Leave them in the dye for less than 45 seconds for a very light tint, or one to two minutes for a medium tint. For a very dark tint or for UV-protective sunglasses, leave the lenses in the dye for six to 12 hours.
Remove the lenses from the dye and unclamp them. Lay the lenses on a clean white cloth to inspect the colour intensity of each lens. Generally, each lens does not tint exactly the same as the next. If this is the case, try to get the two lenses close to the same colour by reinserting one of them back into the dye. A neutraliser solution can also be applied to remove colour from the lens. Be sure to clean excess dye from lenses with a soft optical cloth.
To completely remove the colour from lenses, submerge them into the neutraliser solution for several hours.
Always follow the manufacturer's instructions when adjusting temperatures on tint machines. Most dyes have heat limits and will decompose with overheating.
Be sure to wear safety and protective equipment when working with chemicals.