Dr Hennessy has provided Public and Private sector eye health care for 22 years in various settings.

Dr Hennessy has an active role in the Ophthalmology Network of the Agency for Clinical Innovation (ACI‐ON), a statutory authority of the NSW Ministry of Health. Recently the ACI‐ON has examined public sector eye care pathways for the preventable blindness from cataract, glaucoma and diabetic retinopathy. Dr Hennessy has led the development of an improved pathway for the referral of patients with cataract to NSW public hospitals including a role for optometrists in the pathway.