Screw-in (or Screw-on)
As the name implies, screw-in nosepads are held in place on an eyeglass frame by use of an ultra-small screw. If possible, use the same screws that came with your existing nosepads as there are many different types available of similarly looking nosepad screws that are not interchangeable.
If you lost one of your nose pad screws, you can use the existing one to help locate a replacement, although due to their very small size, two screws that may look alike may easily differ in the type of threading or diameter. If one or both nosepad screws are missing, your best solution may be to obtain a variety of screws from your nose pad vendor.
You will also need a low cost jeweler's screwdriver, but fortunately, many commonly found "eyeglass repair kits" include both a jeweler's screwdriver as well as a variety of common nose pad screws.
Push-in (or Push-on) or Slide-in ( or Slide-on)
Push-in and slide-in nosepads are the easiest to work with as a slight finger pressure usually dislodges an existing nosepad from an eyeglass frame mount, and a similar slight pressure usually secures the replacement nose pad into the "nose pad mounting arm".
For a more in-depth description of nose pad mounting options, please click on the "Mounting" link in the left column of this website.