hello aspirant,

I am sorry to tell you that, you won't be able to join the NDA force with this vision. The vision of a person should be 6/6 without any spectacles. There are a series of eye tests in the medicals after getting recommended in the SSB.

But still you can go to the army aviation branch after the completion of your training in the NDA if your eyes become fit after the training somehow, all you have to do is check , if the army aviation branch eligibility is fulfilled by you or not.

hope that helps