Purpose. There is increasing use of marijuana among young adults and more states in the United States are legalizing medical marijuana use. A number of studies have revealed both the beneficial and harmful effects of marijuana to the human system. Despite some beneficial effects, studies have shown marijuana to have a lot of deleterious effects on the visual system, which subsequently reduces the quality of eyesight. The aim of this study was to investigate if heavy marijuana smoking is associated with a poor quality of eyesight compared with light/no use of marijuana. Methods. The National Longitudinal Survey of Youths (NLSY79), a nationally representative sample of 12,686 young men and women surveyed in 1979 to 2010 was used for this study. The quality of eyesight of 1304 heavy marijuana users was compared with 1304 respondents with light or no marijuana use. The t test, multivariate and weighted logistic regression were used in the data analysis. Results. There was no statistically significant difference in the self-reported quality of eyesight among heavy marijuana smokers compared with youths who never used marijuana or are light marijuana users. Among heavy marijuana smokers, males and high school graduates have decreased odds of reporting a poor quality of eyesight, whereas blacks have increased odds of reporting a poor quality of eyesight. Conclusions. The self-reported quality of eyesight among marijuana users can aid clinicians and other health practitioners facilitate the development of sex-, racial/ethnic-, and educational level-informed prevention and early intervention programs and also help characterize public opinions regarding cannabis, which are particularly relevant given the ongoing debate concerning the medicalization and legalization of cannabis in the United States.