Link : DUBLIN CENSUS RECORDS

[aghadowey]

1851 Dublin City Census index compiled by Dr. D.A. Chart from the original records. This index contains the names and addresses of 60,000 heads of household. The index consists of two hand written volumes which are held in the National Archives (CEN 1851/18/1-2). Also available on CD which also includes scanned images of the 1847 Ordnance Survey Town Plans of Dublin City. 

1901 and 1911 census

Old Age Pension Claims: the introduction of old age pension (min. age 70) c1909 meant 1841 and 1851 census returns were checked as claimants were born before civil registration of births started in 1864. Extracts from these census searches are in the pension claim files.
It is sometimes worth checking for people slightly younger than pension age (surprising how many people weren't as old as they said!) or older siblings whose details can fill in family details such as names of parents and year of marriage, townland, etc.