Additional District and Sessions Judge-VI, Isratullah, convicted Ratan Singh and Tanik Singh and awarded life term to them.
The court also imposed Rs one lakh fine on each of them.
Another convict Brajdev Singh was awarded 10 years rigorous imprisonment in the case.
According to prosecution, the three had poured acid into the eyes of one Upendra Singh over some property dispute and the victim suffered permanent visual impairment.
The incident had taken place on August 29, 1989 at Jiyar village under Asthawan police station area.