What tool is commonly used to isolate natural lashes during the extension application?

The tool commonly used to isolate natural lashes during the extension application is tweezers. Tweezers are essential in the lash extension process because they allow for precise handling of individual natural lashes. When applying extensions, it's crucial to isolate one natural lash at a time to ensure that the extension adheres correctly and remains free from clumping with neighboring lashes. This careful isolation helps achieve a more natural look and prevents damage to the natural lashes.

Other tools, such as scissors, are not designed for isolation and may pose a risk during the application process. Brushes and combs may assist in preparing the lashes or separating them post-application, but they do not offer the necessary precision required to isolate each natural lash effectively. Hence, tweezers are the preferred choice in the application of eyelash extensions.