How to change the brghtness of my notebook pc screen?

I got a toshiba notebook and i got this for a while now I felt my eyes cannot stay for long looking at the screen due to to much brightness and my eyes are always tired after a while looking at this bright screen. I want to change lower the brightness but I dont know how. pls. help. thnksHow to change the brghtness of my notebook pc screen?
control panel, display and its in thereHow to change the brghtness of my notebook pc screen?
try to go to the screen display setting in control panel and play around a little.How to change the brghtness of my notebook pc screen?
Hold down the 'FN' (function) key then press the arrow keys up or down. The FN key is usually to the bottom leftHow to change the brghtness of my notebook pc screen?
Look at the Fn button (short for function). Usually the arrow keys are your brightness keys. Look for the ones labeled with a sun or a half dark half light circle. Hold down the Fn button and push those. They change brightness and contrast.How to change the brghtness of my notebook pc screen?
On your arrow keys, there are little circles that look like suns. Hold down the Fn key (next to the Windows key) and press the down arrow key to make the screen dimmer or up to make it brighter.How to change the brghtness of my notebook pc screen?
just right click and click preference then change screen resolution. set brightnessHow to change the brghtness of my notebook pc screen?
Wear a pair of shades while surfing the net.