Born at Wigan, went to the town Grammar School, and to a school at Chester. In 1859 he entered University College Hospital as a student, and later was House Surgeon there, House Physician at Brompton Hospital, and House Surgeon at the Manchester Royal Infirmary. After becoming FRCS he studied ophthalmology and was Clinical Assistant under Sir William Bowman at the Royal Ophthalmic Hospital, Moorfields. In 1870 he settled in general surgical practice in Liverpool, and opened a free Eye Dispensary in two small rooms in St Paul's Square. The work grew rapidly and attracted voluntary support, so that the house was turned into a hospital - St Paul's Eye and Ear Hospital. From small beginnings the Hospital grew to contain 50 beds with a yearly attendance of nearly 10,000 patients. At one time Walker was Ophthalmic Surgeon to the Royal Albert Edward Infirmary, Wigan, to the Hospital for Skin Diseases, Liverpool, and to the Southport Convalescent Home; Ophthalmic Surgeon to the David Lewes Northern Hospital and to the School for Indigent Blind; Vice-President of the Lancashire and Cheshire Branch of the British Medical Association and of the Liverpool Medical Institution. He made a number of communications on ophthalmology in which he advocated active treatment - ligature of the internal carotid for aneurysm causing exophthalmos; mercurial inunction for intra-ocular inflammation, including sympathetic ophthalmia; subconjunctival sclerotomy for glaucoma; corneal incision for keratitis; division of anterior and posterior adhesions of the iris. He practised at 45 Rodney Street. Towards the end of 1908 his health failed; he sailed to the Canary Islands, and died at Las Palmas on February 15th, 1909. A memorial service was held in the Church for the Blind School, Liverpool, for which he had done so much. He had married in 1870 Louise, daughter of William Nimmo, cotton broker, of Birkdale, who survived him with four sons, one of whom had assisted him from 1902, and two daughters.