Bi-focal lens vs mono-focal len used in cataract surgery?

I heard my eye surgeon mentioned that after cataract surgery with standard implant len (i.e mono focal len).

1) As such, is there any SPECIAL instances that such patients will still be able to read library books like normal people does but with lower contrast? (without using reading glass) or it is generally impossible after surgery?

2) with Bi-focal len i understand that these patients would be able to read their books and see far. But how does it works? Is it a seamless process like a normal person (without visual aid) does or he/she has to read like someone with progress lens does?

3) how does these lens actually looks like physically? I thought its really something like a concave shape len or am I wrong?

I'll try to be thorough , and if you need any thing e-mail me
- you can choose to have any monocular lens you want , either to see near perfectly and use glasses for distance or the reverse .
- contrast is a problem of bifocal IOLs
- it works this way : the lens is formed of 2 parts :
1- optic round the part you see through , got the refractive power , in bifocal the center is more powerful than the periphery and in near work the iris constricts [ normally ] allowing light to pass through the center part only
2- haptics the 2 arms to fix the lens in place
- after the operation vision should remain constant

as far as i know lens used for implant are biconvex monofocal. after surgery one can read books, but it is subjective on the matter of use of external lenses(reading glasses). it differs from person to person depending on prior condition of the eye, corneal condition, adjustments for scarring etc. nowadays seamless bifocal glasses are available where you cant see the demarcating line between the two different lenses, though they are more expensive than the older ones. best to leave the decisions to the professionals.