Whats the career prospect of an Ophthalmologist in the US who has
completed MBBS MS(Ophthalmology) from INDIA? Would he need to write
any exams or go through residency program before starting the practice
in US? If so, what exams/ certifications he will need to earn? And how
easy would it be to get residency in Ophthalmolgy? How long does
residency normally take? How are the job
opportunities in this field? Please provide details with useful links.

This site will take you to all the Licensing bodies in the US, they
will be able to give you the advice, it seems in the US each state has
it's own rules regarding Dr registration. 
http://www.healthsearchusa.com/physicians.html
Good Luck