 is, it's a magnifying power and it's got a term here for refractive index, we won't worry about that. This term here deals with the radius of curvature. The curvier the object, the stronger its focusing power. So if you're short sighted for example, people would say oh I love them, they're shock and weak eyesight. And that's not true, short sightedness is because your eyes are too powerful. The refractive power of your eye is too strong. And if you want to correct for this with laser light, you have to reduce the curvature. Make your eye less bulgy, a little flatter. And that's what they do in laser surgery. We can see here, this isn't a scene from Lord of the Rings, this is what happens in the surgery. What's he doing? Now you are awake while this procedure takes place. And just to let you know, they have those two little hooky retractors either side of your eyelids keeping your eye open. Now you do have a local anesthetic. The rings are so that you'll know where everything has to go back at the end. These are called tram tracks because they're going to cut the top of the cornea off. The cornea is the strongest refracting, the strongest focusing thing in the eye. So you want to flatten that. Here comes the guillotine. Now they don't cut it off the whole way, they just go about three quarters of the way and they create what's called a corneal flap. They're going to lift the flap now with a needle. You'll see the needle coming up from down here. There we go. There goes the flap. Now they're going to use an ultraviolet laser and they're just going to blast away here. And you'll see it starting to go a bit cloudy. And it's just like when you boil an egg, the white of the egg goes white when the protein's denature. So they're using a laser to blast away material from here to make it flatter. The reason that they've created the corneal flap is because at the end they can put it back and it creates its own self-healing, hermetically sealed bandage. It's a very effective technique. If you're considering having it done, it's between five and 700 euros per eye. Now, they're still blasting away there. When they're finished, you'll see them put the flap back now, any minute now. Here we go. That's a little bit of saline just to keep everything nice and moist. There it goes. And here's the beautiful part. They stick the needle back underneath the flap and inflate it with saline just so that you get the ring back where everything was supposed to be at the start. And it's not like they sew the corneal back on. They just leave it there like that. They put a bandage over your eye so you don't use your eye any more than you have to. And that's that. Folks, I'm going to leave it there. There's loads of other things I could have talked to you about, but we've run out of time. So if there's any questions, I'm more than happy to take them. Good afternoon, everybody. I'd like to just take lecture. And is there any questions? Any questions from the audience? Just shout it out. What's the question? Medical Physics has a postgraduate course. There's a very good medical physics course run through St. James's Hospital. You get your degree from Trinity College. And almost, and there's another one in Queens University, but in the Republic of Ireland, the only one that I'm familiar with is the one through Trinity College. So I strongly recommend you go for that. Pardon? Job options. Well, if you go for medical physics, it'll mostly be hospital physicists, radiation therapy, making sure that the X-ray machines are calibrated, those kind of stuff. Any other questions? Yes. Well, the thing about physics is you can end up doing physics in all kinds of strange areas. So physics graduates tend not to have a problem getting jobs. Chemists, you've got to do chemistry, right? Biologists, you've got to do something kind of biological. Where physics is concerned, you do a lot of mathematics, you do a lot of computations, you do a lot of experiments. So you tend to have a very broad portfolio of expertise, and you find physicists working in health, in finance, in computing, electronics. So there are, I would say there are more options for a physicist than there would be for other science graduates. If anybody has any further questions, you can always talk to Dr... I just would like to make a presentation to Dr. McGuigan on behalf of the Institute. Oh, shucks. You shouldn't. And thank you for coming down.