Can you state 5 possible reason why an object may be difficult to see under a properly working microscope?

Question

Can you state 5 possible reason why an object may be difficult to see under a properly working microscope?

Answer 1

thats easy... its invisible like me...lol

Answer 2

1- the object you see has to be coloured with a special teinture so you can see it. so maybe, it's not coloured

2-the object is not properly placed under the microscope

3-the lanes of the microscope is not under one another which causes light not to refract properly

4-the light of the microscope is not put on

5- if you have problems in your eyes