Electoral officials have ordered 40,000 magnifying glasses to help Victorian voters deal with the metre-long Senate ballot paper.

The Australian Electoral Commission (AEC) says this year's document could be the longest in Victorian history.

Up to 57 parties, plus independents, are expected to be listed on the paper.

The AEC's manager, Steve Kennedy, says the cost of the magnifying glasses is just an added expense with so many candidates.

"With the election costing about $108 million, this will probably add about another $15,000 to $20,000," he said.

"To have so many candidates on a ballot paper takes longer to count. That's OK, we will just employ more people."

However, Mr Kennedy added that authorities may have to change the way the ballot is produced in the future.

"Currently we are restricted in the length by what the printers can print for us and also by the laws that govern the election that say that all the parties have to be in one continuous line," he said.

"A couple of things have changed since the last election, [such as] the [nomination] deposits have doubled from $1,000 to $2,000.

"So we are projecting we will have many more candidates on the ballot papers at this election."