It can take up to 8 hours for the eyelash extension adhesive to fully cure the bond between your natural lash and the extensions. Avoid swimming, spas, saunas and tanning on the day of your lash appointment. After the 8 hours, they are able to get wet. While sleeping, lashes can tangle or flip to the side. Brush through your lashes each morning with a clean mascara wand to reshape the extension and keep them fluffed into place. The overall upkeep is very minimal and very easy to manage.