Yes Jyoti, you can join the Indian Army with spectacles that's not a problem but you have to fulfil eyesight criteria according to the type of entry and trade. here are some basic eyesight criteria for Indian Army -  

•  Candidate should be able to read 6/6 in a distant vision chart with each eye with or without glasses. Myopia should not be more than 3.5D and hypermetropia not more than 3.5D including Astigmatism. For women candidates, the minimum acceptable visual acuity are: Distant vision (corrected)better eye 6/6 worse 6/18, Myopia of not more than minus 5.5 including Astogination.
• Internal examination of the eye will be done by means of ophthalmoscope to rule out any disease of the eye. A candidate must have good binocular vision. The colour vision standard will be CP-III for Army A candidate should be able to recognise red and green colours.
• Candidates who have undergone or have the evidence of having undergone Radial Keratotomy, to improve the visual acuity, will be permanently rejected