Ophthalmic surgical equipment is the set of machines and implants used in operations on the eye, mainly cataract surgery and retina surgery. Ophthalmic means to do with the eye. The best-known implant is the artificial lens placed in the eye during cataract surgery, called an intraocular lens (IOL).
A cataract is a clouding of the eye's natural lens, which usually comes with age. The treatment is to remove the cloudy lens and replace it with an artificial one. India performs millions of cataract operations every year, many of them in high-volume eye hospitals and in free eye camps supported by government programmes.
The main machine is the phacoemulsification machine, usually called a phaco machine. The surgeon makes a cut about 2 to 3 mm wide at the edge of the cornea, the clear front of the eye. A probe that vibrates at ultrasonic speed breaks the cloudy lens into small pieces. The same probe sucks the pieces out, while fluid is pumped in to keep the eye's shape. The machine's software balances the fluid going in and the fluid coming out, many times a second. Without this balance, the front of the eye could briefly collapse. The folded artificial lens is then pushed in through the same small cut, and it unfolds inside the eye.
The lens must have the right power, measured in dioptres, or the patient will still need glasses to see far. So before the operation, a measuring device called a biometer measures the length of the eye and the curve of the cornea, using light. Software then uses formulas to choose the lens power. The idea is like choosing the size of an artificial knee from a scan.
For instance, a 70-year-old woman in Tirunelveli has a cataract in one eye. The biometer finds that her eye is 23.4 mm long. The software suggests a lens of +21.5 dioptres, and the surgeon accepts it. The operation takes about 15 minutes, and she goes home the same day. Hospitals with long waiting lists run their theatres through operating room scheduling, so that one surgeon can operate on dozens of patients in a day.
Retina surgery uses a different machine, the vitrectomy machine, which removes the clear gel from the back of the eye. Many retina problems are first found by a retinal camera with AI screening. The microscope that the surgeon looks through can also show the plan on top of the live view of the eye, such as the angle at which to turn a lens. The lens-power software and the planning overlay are both examples of software as a medical device, regulated with the machines under India's Medical Devices Rules.