1851 Census West Hackney, Tower Hamlets

[Westee]

In the 1851 census for the above district, I have noticed that many people have been ticked in the box "Blind or deaf & dumb" - and wondered whether this is correct, or whether the tick relates to something else.  I notice on some pages further on,  the tick is at the side of the page and not inside the box. Whether or not these ticks relate to two issues?  It has always intrigued me as my 5xg/grandfather, his wife and their 2nd child all have the tick in the box denoting 'blind, deaf or dumb'.

[Bookbox]

As sometimes happens, the column for disability has been 're-purposed'. The ticks represent a tally-mark for those born outside the county, in this case Middlesex.

[Westee]

So helpful.  Thankyou.