How does one perform ablution if there is an eyelash lying on the skin layer and it meets another layer when the eye is closed, so that the eyelash only appears when the eye is opened?

The eyelashes are included within the boundaries of the face and must be washed during ablution. If water does not reach the eyelashes when washing the face, then the ablution is invalid. As for artificial eyelashes, it is not permissible to use them because they fall under the category of hair extensions, and "the Prophet (peace be upon him) cursed the woman who adds hair extensions and the one who has them added."