Q: How do I recover lost photos from iPhoto?

Ok. so here's the story. I dropped water on my macbook and computer stopped working. was told there was no damage to hard drive so i bought a hard drive storage and placed my hard drive in said storage. I plugged into another macbook and all my photos were stored. sent my macbook to the apple store and they fixed it. Once it was fixed I put my hard drive back in my macbook. the problem is I seem to be missing photos/videos from the last year.

I did the whole, open iPhoto while pressing option and command buttons to no avail.

i have a lot of videos that i recorded in the last year or so, and i'd really like to try and recover them.

I'm confused because I saw the videos when i placed into another computer, but now, those videos are gone.

If anyone could give me some input. It would be greatly appreciated.

Thanks.