He first attended the Cork School of Design in 1850, and also received some medical edication in Nice, before dropping out and returning to Cork. He matriculated at the Cork School of Design from 1857 to 1860. Despite these anti-establishment activities, O'Hea was commissioned to paint Punchestown in 1868, commemorating the visit of the Prince of Wales to Punchestown races. The painting contained likenesses of the royal party, jockeys and patrons of the races, and prints circulated widely.