Lesley-Anne Alexander, chief executive of the RNIB, has encouraged voluntary organisations to adopt a new model of working in which small charities become associate members of large national charities.
The RNIB has already teamed up with two charities in the sight-loss sector and has now entered preliminary discussions with a third - National Talking Newspapers and Magazines.
The governance model, approved by the Charity Commission, allows the RNIB to become the sole shareholder of associate members, which continue operating under their own names.
Alexander described the model as "somewhere between collaboration and merger or takeover" and said it paved the way for a coordinated national approach to delivering services.
"I hope we are setting a trend," said Alexander, who is also chair of chief executives body Acevo. "When I came to the RNIB I was astounded to find there are more than 700 sight-loss charities. That's lunacy."
Charities owed it to their beneficiaries to make the sector "more logical", she said: "If I had my way, we would have one national sight-loss charity that was responsible for campaigning, infrastructure, strategic marketing and quality initiatives, and a whole carpet of local sight-loss charities delivering services within a framework."
Action for Blind People and the Cardiff Institute for the Blind have already joined the RNIB group. An Action for Blind People spokeswoman said the charity had effectively become an RNIB subsidiary.
The RNIB now markets the activities of Action for Blind People and has withdrawn from services that duplicated its work.
John Kerby, chief executive of National Talking Newspapers and Magazines, confirmed it was in preliminary talks about becoming the next associate. Financial security and the RNIB's national structure were appealing factors, said Kerby. "It would cut out duplication and seems to make sense," he said.
Guide Dogs, the second-largest sight-loss charity, has also been asked to get involved. "It's fair to say they are not keen," said Alexander. "Guide Dogs is obviously the missing component of the association, but we have had positive discussions with other national charities."