Dear Majdi

This article and these links can be helpful for you.

Best.

Mithat

Beck, A. T., Baruch, E., Balter, J. M., Steer, R. A., & Warman, D. M. (2004). A new instrument for measuring insight: the Beck Cognitive Insight Scale. Schizophr Res, 68(2-3), 319-329. doi:10.1016/S0920-9964(03)00189-0

http://www.senyfundacio.org/media/upload/pdf/sdarticle_c7b7018093cb1659511236f772c82bf15.pdf

http://www.ncpsychiatry.org/assets/docs/AnnualMeeting/10_josephgoldberg.pdf

Dear Dr. Durak: 

Thank you very much, I really appreciate your help. 

Dear Dr. Majdi

 You can use parts of "Present State Examination" scale. It is most widely used scale. PSE is an interview schedule. It will also guide you how to ask questions to assess the level of insight.

Dear Mr. Gupta:

Thank you for your concern, I will take it into my consideration.