I am Professor of Ophthalmology and Consultant Ophthalmic Surgeon at Cambridge University Hospital, where I direct the Cambridge Eye Research Centre. I trained at Moorfields Eye Hospital and undertook two Glaucoma fellowships, one there and another at the Shiley Eye Centre/Hamilton Glaucoma Center in San Diego, California.

I specialise in the care of patients with glaucoma or at risk of glaucoma. I am also an experienced cataract surgeon, particularly in more challenging cases that often co-exist in patients with glaucoma. I have more than 15 years experience as a consultant ophthalmic surgeon and utilise the most advanced diagnostic instruments for glaucoma detection and monitoring. I am part of the Faculty of the World Glaucoma Association and as such, am involved in developing glaucoma care guidelines internationally. This gives me insight into the best evidence-based approaches to eye care and treatments that may include phatmaceutical agents, laser treatments, Minimally Invasive Glaucoma Surgeries and glaucoma implant devices (commonly called 'tubes').

To date, I have performed many thousands of cataract surgeries. My NHS practice involves more complicated and challenging cases of cataract and I utilise these skills across the range of cataract operative complexity. I have also performed thousands of laser procedures and more than a thousand trabeculectomy procedures (the most common invasive glaucoma surgery). I have experience of performing the novel Minimally Invasive Glaucoma Surgery techniques such as iStent and Xen implant and shortly the Preserflo device.

I am the Clinical Lead of the Glaucoma Service at Addenbrooke's Hospital (Cambridge University Hospital).  

I have a strong research interest, particularly in advanced techniques of Glaucoma diagnosis and progression and the management of Glaucoma in the community, along with overseas ophthalmology which has involved design and analysis of several large population-based surveys of eye disease, several national in scope, eg. Pakistan, Bangladesh and Trinidad. I am the Chair of the National Institute for Health Research Ophthalmology Specialty Group, responsible for NHS research delivery. I lead the Vision Loss Expert Group of the Global Burden of Disease Study.

In addition to my clinical work I am proud to be Professor of Ophthalmology at Anglia Ruskin University, since 2007. I run a research group at the Vision and Eye Research Institute there and for several years have been the most highly cited researcher at the university. In 2016 and in 2020, I was awarded the Vice Chancellor's Award for Research Exellence and Innovation.

My international work as lead for the Vision Loss Expert Group has involved the coordination of this group of more than 100 ophthalmologists and optometrists with an interest in eye disease at population level. This is the World's foremost independent epidemiology reference group for eye disease and our Global Vision Database has for 13 years been providing the global estimates for vision impairment and blindness, used by the World Health Organization and other agencies. In 2020, I was awarded the Vision Excellence Award by the International Agency for Prevention of Blindness in recognition of my work.