麻烦英语高手将下面一段话翻译成英文，谢绝翻译软件或在线，

Purpose
To investigate the differences among the rates of the cataract victims, surgical operations, surgical operation coverage of the blind caused by cataract and the social costs of the blind caused by cataract with the target research group being on the 50 years old or over who reside in the urban and rural areas of Chongqing City and to therefore provide data basis for the treatment of the cataract victims.

手工翻译，供参考。

Purpose of the investigation::
To investigate the rate of cataract victims among the age of 50 or over 50 years old in ChongQin, and the rate of the being operated, the differences between the coverage of the operation and the different burden of the society on this operation , in order to provid a basis for the cataract prevention.

Objective to investigate the chongqing urban and rural 50 years old and above crowd cataract prevalence, the rate of surgery, cataracts blind surgery coverage and cataract blind society for the prevention and control FuDanLv difference, cataract, provides the basis.

我想这应该是要用于调研报告或之类的（我也常要写这个），所以翻译成了完整的句子，希望对你有帮助。
Purpose:
Through investigating the differences among the rates of the cataract victims, surgical operations, surgical operation coverage and the social cost of the cataract blind who are 50 years old or over in the urban and rural areas of Chongqing City,it provides data basis for the treatment of the cataract victims.

perpose: investigate the rate of catching cataract among the 50 or over 50 years old in ChongQin, and the rate of being operated, the differences between the coverage of the operation of the blind and the burden of the society of this operation of the blind, providing a basis for the cataract prevention.