目的 掌握小学阶段学生随年级增长视力变化数据,为小学生近视防控工作提供参考,促进预防近视工作. 方法 选取密云县第三小学2008级全体新生为调查对象,按照《北京市中小学生健康体检管理办法》检测标准要求,进行为期6年视力水平跟踪调查,并对学生假期用眼情况进行分类统计. 结果 通过对2008级156名学生6年24次连续跟踪调查,视力不良率由入学时的26％增长到毕业时的82％,视力不良率随年级升高明显上升;假期学生用眼强度较大,主要是课外学习班、看电视和假期作业,对视力水平有明显影响. 结论 小学生视力不良高发,应加强预防和干预措施,降低学生用眼强度.

视力是眼科临床常规进行诊断和疗效评估的重要依据,了解近视眼的视力表现对于临床诊疗具有实际的意义.一些经典的论著对于近视眼和视力之间的关系都已有所论述[1-4].本文对近视眼的裸眼视力相对于其近视度数偏高的现象进行临床观察,并对这一现象的原因进行分析讨论.

Objective Registration flicker on eye fundus images that were screened in different time is important for ophthalmologist to study the glaucoma,diabetic retinopathy.Methods The normalized mutual information could be used to deal with eye fundus images and flicker them every one second.There are two methods to estimate it: one is based on the error of eye fundus images registration,the other is according to testing by ophthalmologist.Results 50 eye fundus images were tested and repeated ten times.Circumvolve and shift value had been analyzed. The result is P>0.05.100 eye fundus images had been matched.Conclusion Image registration methods based on mutual information had been accepted as the accurate and efficient method in eye fundus images registration flicker.It is easy to operate and repeat.

Objective To realize metrological dynamic management in a modern hospital.Methods The problems in metrological management in hospitlal were summed up. The digital metrological management was put forward to solve the problems.Results The dynamic metrological management. was designed and applied. Conclusion It is important to realize metrological dynamic management in modern hospital in order to ensure accuracy of medical device and improve medical quality.