This paper will focus on the use of optical treatment to improve control of intermittent exotropia and the effects this treatment method has on refractive error. Minus lens therapy is a non-invasive treatment for young children in which control of intermittent exotropia is improved by inducing accommodative convergence. Studies have found a significant decrease in the angle of distance exotropia with this treatment method. Improved stereoacuity and decreased suppression responses on Worth-4-Dot testing have also been demonstrated. However, older children and adults may experience asthenopia due to excessive accommodative effort. Additionally, it is theorized that the excessive accommodation may result in myopia. One study found that participants using overminus lenses had a greater shift in myopia compared to a non-overminus group. This finding was still present 24 to 36 months later. The mechanism causing an increased shift in myopia in these studies is unknown. Many other studies have examined this possible myopic shift and found no statistically significant change in refractive error. One study found a myopic shift in both an overminus and observation group with a greater shift in the overminus group although it was not statistically significant. The shift in both groups was in range of normal refractive growth. Baseline refractive status has been found to have a correlation to myopic shift, in that those with myopia at baseline experience a greater shift. Therefore, the myopic shift that was found in one study may be due to a higher proportion of patients with myopia at baseline.In conclusion, overminus lens treatment appears to be a safe and effective treatment method for patients with intermittent exotropia. Future research on this topic could focus on the effect of optical treatment for intermittent exotropia in children with high myopia or myopic risk factors.