It depends on what kinda of false lash you are going for. There are three main types:
1: false strip lashes - you get them in boots etc are one long strip that goes on your EYELID and will last 2-8 hours at best
2. False cluster lashes - a group pf 3/4 lashes which are applied to your EYELID, normally around 10-12 are applied, last 2-8hours at best.
3. Eyelash Extensions - around 50 are applied to each individual EYELASH, will remain glued to each lash for the length of the lash's life, normally around 28days. This means you will lose false lashes as your natural ones renew themselves, which is what normally happens. A lot of people don't realise your eyelashes grow and fall out every 28days, all at different stages so you are never baldy. Eyelash extensions can be done is a huge range of length, thickness and shape to suit your requirements. When done properly they are fabulous. It is always best to find someone who has a good range of lashes, as many salon's only have a couple of sizes and they may not suit you.
Eyelash extensions can be taken of easily by a salon, they will have a solution which disolves the glue safely, leaving your lashes perfectly fine.
(btw I do extensions for a living so I know what I'm saying
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