目的：观察青年人群近距离用眼后眼部生理及功能性参数的变化及恢复时间。

方法：前瞻性研究。随机选取2019-12/2020-06在我院进行医学验光的患者69例138眼，根据主觉验光结果分为正视组(+0.75D≤等效球镜度≤-0.50D，18例36眼)、低度近视组(-0.75D≤等效球镜度≤-3.00D，25例50眼)和中度近视组(-3.25D≤等效球镜度≤-6.00D，26例52眼)。所有受试者近距离阅读20min后远眺放松20min，分别于近距离用眼前、近距离用眼20min后、远眺5、10、15、20min时测量受试者眼部生理性参数\〖前房深度(ACD)、眼轴长度(AL)\〗和功能性参数\〖正相对调节(PRA)、调节反应(BCC)\〗，分析各参数的达极时间和恢复时间。

结果：近距离用眼后眼轴变长，前房变浅，PRA绝对值变大，BCC无明显变化，75%(52/69)的受试者AL在近距离用眼20min后达极，87%(60/69)的受试者ACD在远眺5min时达极，96%(66/69)的受试者PRA在近距离用眼20min后达极，且以上参数均在远眺10min后逐渐恢复至初始状态。

结论：近距离用眼后眼部参数发生改变，眼轴变长，前房变浅，PRA绝对值增大，但均在远眺放松过程中逐渐回退，且均需要10min以上才能恢复至初始状态。

METHODS: A prospective study. A total of 69 patients(138 eyes)who underwent medical optometry in our hospital from December 2019 to June 2020 were randomly selected. According to the results of subjective optometry, they were divided into the emmetropia group(+0.75D≤ spherical equivalent ≤-0.50D, with 36 eyes of 18 cases), the low-degree myopia group(-0.75D≤spherical equivalent ≤-3.00D,with 50 eyes of 25 cases)and moderate myopia group(-3.25D ≤ spherical equivalent ≤-6.00D, with 52 eyes of 26 cases). All subjects overlooked for 20min after reading at a close distance for 20min. The physiological parameters \〖anterior chamber depth(ACD), axial length(AL)\〗 and functional parameters \〖positive relative accommodation(PRA), cross cylinder(BCC)\〗 of the eyes were measured before close visual work, 20min after close visual work, and 5, 10, 15, and 20min after overlook, respectively. The time to reach the pole and the recovery time of each parameter were analyzed.

RESULTS: After close visual work, the AL became longer, the ACD became shallower, and the absolute value of PRA became larger. There was no significant change in BCC. AL of 75%(52/69)of subjects reached the pole after 20min of close visual work, and ACD of 87%(60/69)of subjects reached the pole after 5min of overlooking. In 96%(66/69)of the subjects, PRA reached the pole after 20min of close visual work, and the parameters above gradually returned to the initial state after 10min of overlooking.

CONCLUSION: The ocular parameters changed after close visual work, of which the AL became longer, the ACD became shallower, and the absolute value of PRA increased. However, all of them gradually retreated during the process of overlooking, and all the parameters needed more than 10min to recover to the initial state.