Hints to Better enjoy Memrise 
- Use f.lux(http://justgetflux.com/), it will help your eyes in the long run.
- Position the monitor in your eyes height in a manner you look directly straight.
- Sit at least 60cm from your monitor.
- Turn on your room light on at night.
- More ergonomic hints here(http://ergonomics.about.com/od/office/ss/computer_setup.htm).
- Take a break from 5 to 15 minutes for each hour using the computer.
- Do not plant more than you can handle. Each person has his/her own pace to learn new items.
- If you start getting headaches (personal experience) take a good break, breath deep and slowly, drink lots of water and try to distract with something else (preferable not in the computer).
- Remember to reserve some time to walk or to do exercises.
- You can press Enter key two times quickly after typing a word to skip the delay between words appearance.
- You can bookmark your most used pages, such as General Discussion Forum or current Courses into a folder at the bookmarks toolbar; then if you click with the mouse middle-button at the folder it will open all pages in new tabs for you (hint for firefox users, I don't know if it works the same way in other browsers).
- Make use of Memrise hotkeys , they are great!
- Most of times, creating your own Mem will help you retain the word better in the long run. Any type of Mem is ok if it helps you remember the item; however, remember children and schools also use Memrise, try to make safe Mems whenever possible.
- You can press CTRL + "+" to zoom in your screen/font size. CTRL + "-" will zoom out and CTRL + 0 (zero) will reset the zoom level to default. This is useful if you are learning single characters (like Japanese Kanji for example).
 Thanks to people of this thread : http://www.memrise.com/thread/1296772/