If your screen has become extremely contaminated, such as with fingerprints, oils, or some other foreign contaminant, you have a few options. First, it is possible to wash the screen, if appropriate precautions are taken. Avoid this if at all possible, but if you have serious dirt or oil that won’t respond to the gentler methods, here is the appropriate procedure. Get a very soft artist’s brush – red sable works well. Wet the screen with warm tap water; place a drop of liquid dish soap (like Dawn) directly on the screen. Wet the brush and work the soap thoroughly into the screen. On the matte (prism) side, you can use any motion you’d like. On the other side, there is a Fresnel lens that has a series of concentric grooves; to clean them properly, you will need to work in circles starting at the middle and getting progressively larger. When you’re done, rinse thoroughly in warm water using the brush to help to soap get off. Then, follow with another thorough rinse, this time in dead cold water. Finally, blow the water off the screen with canned air (making sure not to freeze it) or a big bulb blower (like a rocket blower). The key is to blow the water off the screen before it can evaporate and leave water spots. Distilled or de-ionized water will be less prone to leaving water spots and should be used as a final rinse, before drying, if it is available.
As a safer alternative, we would be happy to clean your screen for you here at Katz Eye™ Optics and we can usually do this free of charge. If you would like to send your screen in, please contact us first to make appropriate arrangements.