AIM: To investigated the refraction and cycloplegic effects of 0.5g/L tropicamide eye drops in various low myopia age groups, and provide clinical guidelines for proper usage of cyclopegic agent in different population.

METHODS: Three low myopia age groups(n=45)were selected, non-cycloplegic and cycloplegic auto-refraction using “Shin-Nippon” auto-refractor were performed at various time point for refractive error. The subjective accommodation amplitudes were also collected at each time point.

RESULTS: The accommodation amplitude showed a similar but significant decline between 20～60min after the first cyclopegic drops in all three age groups. However, the decline of accommodation amplitudes were not statistically correlated with the results of “Shin-Nippon”auto-refraction results at different time points.

CONCLUSION: The refraction time should be arranged according to the cycloplegic effects of tropicamide. Open-field auto-refractor could reduce the usage of cycloglegice drugs in low myopia groups, even for the youngest.