Objective: To evaluate the content, quality, and reliability of keratoconus-related YouTube videos as sources for patient education. Methods: YouTube was queried using the keywords "keratoconus," "contact lenses for keratoconus," "corneal cross-linking," and "corneal transplant surgery for keratoconus." Two ophthalmologists independently classified videos as useful, misleading, or patient testimonials and rated them using the DISCERN score (range, 16-75), Journal of the American Medical Association score (JAMAS; range, 0-4), Global Quality Score (GQS; range, 1-5), and Keratoconus-Specific Score (KSS; range, 0-32). Interrater agreement was analyzed using intraclass correlation coefficients. Multivariate linear regression models were fitted to identify factors associated with quality and popularity indices. Results: Of the 300 videos screened, 201 were included in the study, 58% were classified as useful, 13% as misleading, and 29% as patient views. Overall video quality was poor, with an average DISCERN score of 22, JAMAS of 1.2, GQS of 1.8, and KSS of 4.5. Misleading videos scored significantly lower than average but had higher popularity compared with useful videos. Video length inversely correlated with popularity index. Television shows were more likely to share misleading information than other uploaders, whereas all videos uploaded by university channels provided useful information but constituted only 12% of all videos. Conclusions: Videos rated the best source of information were not the ones most popular. YouTube has great potential to change the attitude of individuals both for and against the right choice. Therefore, health professionals should act to use this potential in favor of effective and reliable health communication.