OPTOS, the Scottish eye testing company, has agreed to be bought by Nikon of Japan in a £259m deal which provides a stunning endorsement of the technology pioneered by the company's founder Douglas Anderson.

The engineer founded Optos with £80,000 backing in 1992 after his then five-year-old son lost sight in an eye when a retinal detachment was detected too late for treatment. Mr Anderson determined to develop a product which could provide a view of the whole retina in one image.

The Dunfermline-based company has gone on to build an international business with around 7,000 of the devices it has developed in use around the world.

Nikon, best known for its cameras, wants to buy the firm to help lead a push into the global medical imaging market. Kazuo Ushida, President of Nikon, said: "I am confident that an Optos/Nikon combination would create a world class "retina" player."

The planned 340p per share cash takeover of Optos by the Japanese giant would provide lucrative reward for the faith shown in the firm by pioneers of Scotland's business angel movement.

Investors including Mike Rutterford and Barry Sealey provided £80,000 start up funding for Optos in 1992 in the first deal by what became the Archangels syndicate.

Mr Rutterford retains a million shares valued at £3.4m by the takeover offer.

Mr Sealey said he was pleased as a longstanding shareholder in Optos. Gavin Gemmell, a former senior partner of Baillie Gifford fund managers, is also a shareholder.

If approved by shareholders, the takeover will result in control of another Scottish company shifting overseas. This will provoke concern in some quarters.

Stock market listed firms like Optos boost Scotland's standing in international markets and provide valuable work for the advisory community.

But Optos' chief executive Roy Davis noted Nikon will retain the firm's base in Dunfermline, where it has research and development and manufacturing facilities and employs 180 people.

Nikon said it does not have any current plans for headcount reductions at Optos.

Mr Davis said: "They intend to invest in us and that will mean ultimately more jobs for Scotland,"

Noting that the price offered represents a 30 per cent premium to Thursday's closing level for Optos shares, Mr Davis said: "There's a duty to allow our shareholders to decide on that."

Mr Anderson said the offer was pitched at a "nice premium". He said he has a shareholding in Optos but did not disclose the size of the interest.

The inventor added: "They've made it pretty plain their commitment to keep research and development and manufacturing in Scotland... That's probably the most important thing for me."

The deal cements a remarkable achievement by Mr Anderson, who used his engineering skills to revolutionise testing of the retina.

Mr Anderson recalled seeing his son undergo examinations and being shocked by the limitations of the tests concerned.

"I said all that looks really primitive," he noted.

"It was obvious in a couple of seconds that you needed something that could look at the whole retina that was comfortable for the child and easy for practitioners to use."

Mr Anderson showed enough enthusiasm and commitment to the idea of developing a product to enable him to win backing on the basis of a rudimentary business plan.

"We bought into it before he told us about the special interest and his son. We did not buy it on a sob story," said Mr Sealey.

The deal provided a model for backing exciting early stage firms which Mr Sealey and Mr Rutterford formalised in the Archangels syndicate.

Syndicate members went on to back a series of fund-raisings by Optos, which launched its first product in 2000.

Mr Anderson said around 400 other funders declined to provide backing.

Asked if he ever thought the venture would fail, Mr Anderson said: "My basis of operation is you've not failed yet so just keep going."

The company floated on the London Stock Exchange in February 2006, valued at around £170m.

It has struggled at times to attract investor interest on the exchange.

Mr Davis noted shares in the firm traded at just 34p soon after he joined in 2008.

They fetched 150p four months ago.

At last week's general meeting Mr Sealey and Mr Rutterford said Optos had reached a stage where it should reward investors with a dividend.

The company grew underlying pre-tax profits to $18.5m in the year to September, from $9.2m to $18.5m.

Shares closed up 31 per cent, 81p, at 341.5p.