According to your sign and symptom you are suffering from some infection gastric problem with headache and blurring of vision.
As you know that best treatment depend on the correct diagnosis and correct diagnosis depend on the complete history of the patient so please take consultation from a doctor and give complete history of the patient so that correct diagnosis will be make and then best treatment will be start
Next Steps
Yeah after intake of vaccine that problem can be occurs because when week virus enter in your body then body immunity will fight against that virus and antibody will form and these phenomenon occurs in every organ of body so that any organ can show some side effect like headache and gastric problem and blurring vision.
Vaccination is good to get immunity but
most importantly you should follow good life style as take plenty of fluid like 4-5 litre water per day and
take less spicy and fatty food
and do excercise regularly with yoga and meditation.
Health Tips
Please follow good life style and keep positive attitude to fight any problem of your life.