Aim: To evaluate the effects of orally administered black-currant (BC) extract on the enlargement of globe component dimensions induced in chicks by wearing negative lenses. Methods: Negative lenses (–8 D) were worn on the right eyes by 8-day-old chicks, and their fellow eyes acted as controls. BC extract and distilled water (vehicle control) were orally administered once a day for 3 days. To confirm the effect of BC anthocyanins (BCAs), they were intravenously administered once a day for 3 days. Dimensions of globe components of right eyes and fellow eyes were measured with an A-scan ultrasound instrument on the third day (day 4) after placement of the negative lenses. Results: Orally administered BC extract significantly inhibited enlargement of vitreous-chamber depth, axial and ocular lengths in a dose-dependent manner when compared to controls. Intravenously administered BCAs also inhibited elongation of vitreous-chamber depth and axial length when compared to controls. Conclusions: This is the first evidence that BC extract and BCAs could inhibit enlargement of globe component dimensions in a negative lens-induced chick myopia model.