英语翻译：场景如下

“我在国外”是说楼主目前人在国外，他/她需要去眼镜店测视力，只要翻译他/她该如何和店员沟通就行了。不用把i am aboard也翻译出来吧！
i need to have an eyesight test and a certification after that.
我对“certification”或者“certificate”仍然有疑问，因为这两个单词都是关于正式的证明某种能力、技能的证书。显然关于一个视力测试的证明只是需要一个结果而已，我想不应该用如此正式的单词。可是暂时又想不出来该用什么词。大家集思广益吧。

I'm in China right now, need to go to a store to test my eye sight, please send me a certificate

I am on abroad, I need to go to a eyeglass store to test eyesight, and then ask him to open a prove.

I'm in abroad and need to test my sight in a glasses shop,then I want him to show me an evidence.