Background. Body mass index (BMI) is a person's weight in kilograms (or pounds) divided by the square of height in meters (or feet). Obesity affects a wide spectrum of age groups, from the young to the elderly, and there are several eye diseases related to obesity like diabetic retinopathy, floppy eyelid syndrome, retinal vein occlusion, stroke-related vision loss, age-related macular degeneration, and possibly, refractive errors. Refractive errors (RE) are optical imperfections related to the focusing ability of the eye and are the main cause of visual impairment which may result in missed education and employment opportunities, lower productivity and impaired quality of life. Aim. The study aimed to find an association between body mass index (BMI) and refractive errors. Methodology. A cross-sectional study was designed to involve a representative sample of medical students in Al-Kindy College of medicine, from December 8, 2021 to January 10, 2022. Weight and height were measured. BMI was estimated, and their refractive error was assessed. Results. A total of 400 students participated in the study, of which 191 (47.8%) had refractive errors, whereas 209 (52.2%) were emmetropic. Thirty-seven point eight percent of the participants had BMI > 25. A significant relationship between refractive errors and all BMI groups was found (p < 0.025). Compared to normal weight group, overweight and obese groups, only the underweight group showed a significant relationship with refractive errors, p < 0.006. Conclusion. Myopia is associated with being underweight, hence the link between the two is statistically significant. The severity of this condition, however, is unaffected by body mass index. Myopia was not a concern among students with normal or high body mass index (BMI).