The purpose of this study was to determine refractive error changes across time and to define factors contributing to decompensation in patients with fully accomodative esotropia (FAET). This was a retrospective study of 223 patients with a mean age at presentation and onset of 5.36 ±2.26 years and 2.23 ±1.31 years respectively. Forty-six percent were female. Mean spherical equivalent was +4.58 ±2.01D and +4.82 ±2.01D with mean visual acuity of 0.4 ±0.09 and 0.07 ±0.16 logMAR for right / left eyes respectively. Mean follow-up was 5.94 ±0.31 years. At initial visit, 62.8% had amblyopia reducing to 29.6% at follow-up. Spherical equivalent changes from initial visit to seven years and from 12-17 years were significantly different with decrease of hypermetropia of 0.13D per year and 0.06D per year, for 7-12 and 12-17 years. Hypermetropia increased up to age seven years and then decreased; 18.4% discontinued glasses during follow-up. These had significantly lower prescriptions than those continuing with glasses. Angle of deviation deteriorated in 13.5% at a mean of 6.20 ±3.6 years from onset and required surgery. These were most often boys, in those with older presentation age and those with near-distance disparity and inferior oblique overaction.