The under-eye is one of the most-requested and most-unforgiving areas in aesthetics, and the choice between approaches like PRF and filler there carries unusual consequence. Both can be considered for under-eye concerns by different routes, but the area's delicacy makes careful, cause-specific clinical assessment essential — far more than a generic "which is better."
This is general education for owners, not medical advice. Assessment and selection are clinical decisions for trained providers.
