Introduction: To compare mean best-corrected visual acuity (BCVA), retinal sensitivity (RS), and bivariate contour ellipse area (BCEA) in patients with adult-onset foveomacular vitelliform dystrophy (AOFVD) and healthy subjects (HSs), reporting also functional disease-related changes in the different stages of the AOFVD disease. Materials and Methods: In this observational cross-sectional study, a total of 19 patients (30 eyes; 12 female and 7 male) with AOFVD were enrolled, and 30 patients (30 eyes; 16 female and 14 male) were recruited as age-matched control group (74.36 ± 9.17 years vs. 71.83 ± 6.99 years respectively, P= 0.11). All patients underwent a complete ophthalmologic examination, fundus autofluorescence and fluorescein angiography, spectral-domain optical coherence tomography and microperimetry (MP)-1 analysis. The data collection included mean BCVA, mean RS measured by means of MP-1, BCEA, and central retinal thickness. Results: All the functional parameters (BCVA, RS, and BCEA) were significantly worse in AOFVD group than HS. Subgroup analysis showed that the most significant functional changes, quantified by mean BCVA, RS, and BCEA, were in the atrophic stage (P = 0.03, P= 0.01, and P= 0.001, respectively). All the functional parameters were well correlated in the different stages. Conclusions: This study further confirms the good visual prognosis in the AOFVD eyes. Fixation stability measurement using BCEA demonstrates good evaluation of visual performance integrating traditional functional parameters. It may also serve for further rehabilitative purposes in atrophic eyes.