OBJECTIVES: The Eyelash Satisfaction Questionnaire (ESQ), a static measure, has been previously validated for the assessment of eyelash-specific patient-reported outcomes (PROs) in subjects receiving a therapeutic treatment for hypotrichosis of eyelashes.  The current study aimed to validate a similar questionnaire, the Eyelash Satisfaction Follow-up Questionnaire (ESFQ), a 39-item dynamic measure designed specifically to self-assess eyelash-specific PROs.   METHODS: The ESFQ was initially examined in a 909-person validation sample consisting of online respondents.  Confirmatory factor analysis (CFA) was initially used to test the measurement structure of the questionnaire.  Item- and scale-level psychometric properties such as item-total correlations, internal consistency, and convergent and discriminant validities were reviewed.  The ESFQ was then used in a clinical population receiving bimatoprost ophthalmic solution 0.03%, a product that improves eyelash prominence, during a 16-week randomized, controlled, masked, clinical trial. RESULTS: Initial CFA results revealed a “good fit” based on hypothesized similarity with the factor structure identified in the ESQ.  A model using 9 indicators (3 per factor), similar to the structure of the ESQ, was chosen as the optimal method.  The final model showed good internal consistency along with convergent and discriminant validities.  However, the alpha-removed statistic for the length, fullness, and overall satisfaction (LFOS) construct showed a significant increase in scale consistency with the removal of item 8 (Compared to your first visit, overall, how satisfied are you with your eyelashes now?).  Despite this, the model structure was retained to better facilitate comparisons between the ESQ and ESFQ and to provide sufficient measures to properly evaluate the construct.   CONCLUSIONS: The 9-item ESFQ appears to be a valid measure to assess changes in eyelash-specific PROs.  The factor structure showed near equivalence with the ESQ.  Future research will involve further validation of the ESFQ in response to variations in hypotrichosis etiologies and clinical treatment paradigms.