There is no way to increase the size of a photo image once it's been scanned/taken. If you want larger images from a scanned image scan it at a higher resolution, dpi.
Additionally, with the amount of information you've provided it's impossible to offer a solution. We can't see your computer so we need to know the details of your problem and setup, i.e.:
- what version of iPhoto are you using?
- what system version are you running?
- what do you mean by "view designation"?
- what fixes have you tried?
- where is your library located?
- did you apply any updates or upgrades just prior to the problem occurring?
- are you running a "managed" or "referenced" library?
- what type of Mac?
- how much free space on your boot drive?