Eyeball photography tutorial. 50mm 1.8 Nikon, teach me?

I have a Nikon D5100, I have a kit lens and a 50mm. F1.8
I wish to learn to take pictures of eyeballs, close shots, with great detail, something like this
http://www.shutterstock.com/pic-81113065/stock-photo-macro-shot-of-a-woman-s-eye.html

Are the equipments I have enough to do this? If yes, can you guys teach me the settings, and what types of surroundings i would need for a shot like this?

Point your camera at the persons eye and take the picture

You have the wrong lens.

You need a macro lens like the Nikkor AF-S 60 mm f/2.8 lens

^ yes you need a macro lens to cspture the eye and all the details a lot better. And then point the camera at the persons eye and take the picture

The most obvious way is to get a macro lens but there's a much cheaper way of doing it.
You can use your 1.8 lens and add an extension tube which will bring the minimum focus point closer to the camera.
They are incredibly cheap and can be used on any lens you buy in the future.
This is the absolute cheapest
http://www.ebay.co.uk/...0809223944
You will lose autofocus and aperture will be at its widest but it's a small price to pay.