Despite the name, eyelash perms are not permanent. The results of an eyelash perm typically last 6-8 weeks, or the natural growth cycle of the eyelashes. When the permed eyelashes naturally fall out, the new eyelash hair will grow in straight (as it was before your eyelash perm). If you are using a lash growing product such as Latisse, you may notice new hair growth sooner and you may need to come in around 4-5 weeks but as the lashes fill in you will be able to go longer between lash perming. Clients with shorter lashes typically come in around 4-5 weeks. Medium to long lash clients can go 8 weeks or more.