Abstract: To observe the effect of concave and convex on growing and the refractive developing of guinea pig eyes and to establish lensinduced animal model of myopia or hyperopia. Methods: Fortyseven 34week guinea pigs were randomly divided into 7 groups, who wore different degrees concave or convex spherical lenses on their right eyes and none on the left eyes as control. The axial length and refraction were measured before and 11 days after wearing lenses. Results: On the 11th day after wearing lenses, the lenswearing eyes of group +4.00D and +8.00D became hyperopic (on average +1.46D， and +1.58D, respectively )（P＜0.05), whereas of group -4.00D, -8.00D， and -15.00D became myopic (on average -2.92D, -3.17D， and -3.10D, respectively )（P＜0.01), and of group 0.00D and -2.00D had not significantly changed（P＞0.05）.　There was no significantly different in axial length among all 7 groups（P＞0.05）. Conclusion: Guinea pig eyes can be influenced by lens, suggesting it can be used as a simple economic mammal model in myopia or hyperopia study.

Key words: Refractive error, Guinea pig, Lens, Axial length