Sorry to interupt. But I had replied to your follow up question in the previous question itself. As you have not seen that I shall send the answer here.
Yes , surely all the necessary investigations would have been done if you have been there for the reduced vision
in one eye. The usual protocol followed for reduced vision in one eye is-
1) vision test followed by refraction
to look for improvement with glasses
2) examination of the eye under slitlamp to look out for any central corneal opacity which can contribute to reduced vision ( peripheral lesions do not affect vision much , this type of visual impairment is more gradual) .
3) Fundus examination in which the back of the eye is tested such as retina and the optic nerve ( pupils are dilated in this test)
Surely if any cause is there for the reduced vision , it should be picked up in one of these tests.
Thank you and best wishes
press the accept button again as you have already done so.