Eyelash extensions are used to enhance the length, curliness, fullness, and thickness of natural eyelashes. The extensions may be made from several materials including mink and synthetic hair. The main method of applying the extensions on is by using an adhesive glue to individually sticking them to the eyelashes one-by-one. This is to prevent the eyelashes from sticking together. False eyelashes and eyelash extensions are not the same.
Semi-permanent lashes, also known as individual eyelash extensions, are eyelashes applied with an adhesive which is usually cyanoacrylate. There are different types of cyanoacrylates including ethyl, methyl, butyl, and octyl, which is designed for bonding to different surfaces. Lash adhesives are made from methyl-2-cyanoacrylate which is designed to bond a smooth surface (the eyelash extension) to a porous surface (the natural eyelash). It is designed to be used around the eyes and on the natural lashes, but not on the skin which can cause irritation.
Eyelash extensions give the appearance of having mascara on without the messy clumps and smudging of makeup. Generally, a single lash is applied to each natural lash. When applied properly, neither the eyelash extension nor the glue should touch the eyelid because it may cause irritation. This was design to last until the lashes naturally fall out, which is usually around 3–4 weeks. After those 3-4 weeks, new lash growth will need to be bonded, making lash extensions a regular monthly service if one wishes to maintain the full look.