Brief Answer:
dibetes vision problem in one eye.

Detailed Answer:
Your mother has got history of diabetes, which should be properly controlled. Now fundus examination is to be done to rule out diabetic retinopathy. If retinopathy is detected then capilary bleeding of blood vessels is to be sealed by laser coagulation. Most important is proper blood sugar maintenance, change of life style with more physical activity like regular morning walk. Proper diet control is essential. In your case refraction is required and in case of need she should be supplemented with new diabetic drug regime is to be reviewed. It is to be seen whether she is insulin dependent. Glycolated hemoglobin test should be done.

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Brief Answer:
yes, eye test is needed

Detailed Answer:
you can do the test and communicate, I will try to advise, you may also consult a diabetologist near about your place.

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