If you fail to obtain the eagle eye achievement during your play through of the game simply start up the bonus chapter, skip the cut scene and use the map to travel to the laboratory and click on the bookshelves in the back corner of the room to start a hidden object game...

- The deer is a black silhouette image on the wall above the open box/create (with an "L" on the inside of the lid)

- The gavel (a wooden hammer used by auctioneers) is leaning up on the front of the chair

- The leaf is just above the gloves, which are at the base of the right ladder leg

- The starfish is just left of the open box/crate (as mentioned earlier) on the bookshelves (the funnel is just left of the starfish and the megaphone is on the far left of the same shelf)

- The rolling pin is on one of the cart wheel spokes (at about 10 o'clock)

- The flask is concealed within the book just resting to the left of the open box/crate, again as mentioned earlier. Just click the book to open the clover and click again to take the flask

- The empty bag is on the right hand bookshelves, this takes the form of a small hessian bag filled with seed or some such, just right of the basket of apples. Just click the bag until it is empty and then click the bag again to take the empty bag

- The box lid, is not the lid of the box/crate mentioned earlier, in fact, you want to click on the opening to this box which brings up a window showing the objects within and the lid you want the small white one with a bow on it

- The calliper is resting on the two cart wheels at about 5 o'clock (not so easy to spot at first glance)

- The shell is on the chair to the right of the inkwell & feather

- The sun (another black silhouette image) is on the right frame of the right set of bookshelves (just look to the right of where the empty bag was collected earlier)

- The piece of cheese is again also the open box/create and is found in the jaws of the false teeth

Now if you fail to do the hidden object game in under 60 seconds, save and exit, start up a new main game, save and exit and start the bonus chapter again and head to the lab to try again (otherwise you just start where you left off), alternatively you could just force close the game to avoid saving (which takes longer and isn't advised). Personally, I managed to get the achievement in less than 5 minutes using this method, hope this helps!