Daysoft, the South Lanarkshire-based maker of disposable contact lenses, is expanding its staff and its manufacturing space as online sales into overseas markets drive further growth.

The company founded by veteran entrepreneur Ron Hamilton has this week recruited 10 new staff and completed the foundations for a factory extension and new access road at its Blantyre headquarters which will open in October.

It will be the company's third expansion in four years and boost manufacturing capacity of Daysoft's throwaway lenses to 100 million a year, 50% above the site's current output.

Chairman Mr Hamilton, 71, said: "We are continuing to experience solid sales and profit growth again this year but there is no greater business satisfaction than to be able to increase our 200-strong workforce.

"Our building expansion is in anticipation of continued growth into 2014 and this building investment is just one part of our £1.2 million capital spend programme for 2013."

Daysoft's 2012 profits were revealed in June to be down 25% at just under £1m, hit by the Government's tax crackdown on retailers shipping low-value consignments from the Channel Islands. But sales were up 4% at £9.3m, and the group moved during the year from net debt of £1.2m to funds of £2.9m.

Mr Hamilton commented: "We have had a great first seven months of the year, pretty much in line with what we were hoping to do, and we will probably add more staff between now and Christmas.

"Headcount is the ultimate demonstration of how the business is going, we manage our production, sales and stock levels and try to get that balance right. We are getting 1000 new customers every week, and 30% of our online business is now into export markets."

Daysoft opened in 2002 in the Hamilton International Technology Park, with £2m of the proceeds from Mr Hamilton's £17m sale of his pioneering disposable contact lens business Award in Livingston five years earlier, and a 27% stake held by Scottish Equity Partners.

Award's owners Bausch & Lomb transferred all the Scottish production to Ireland in 2006.

Meanwhile, Daysoft, which had begun by selling lenses wholesale to independent opticians in the UK and overseas, launched its direct-to-consumer business the same year when competition was fully opened up in the retail market.

Mr Hamilton said: "We sell quite strongly into key distributors in Hong Kong and Singapore but we also sell online in those locations."

Daysoft has to use its Jersey distributor to evade restrictions on the sale of lenses in the UK.

On the resistance to his business model from parts of the industry, Mr Hamilton said: "The point that is missing in the minds of a lot of people is we are expanding the market in the same way that low-cost airlines do. It is all about repurchases - do you need to have a high-cost structure in the high street to make a repurchase of something which is now so well engineered that it is highly reliable."

The founder has said that without the online route to market "we would have been owned today by Specsavers or doing the own-branding for Tesco".

He said yesterday: "We have pursued a strategy of steady, incremental, expansion grounded on strong worldwide sales growth using our unique e-commerce website. I am especially proud that Daysoft is a manufacturing business firmly based and owned in the UK where we design our lenses and our process equipment."

Daysoft has had several regional selective assistance awards from Scottish Enterprise totalling more than £1.5m.

Mr Hamilton said: "We have been very fortunate getting support from RSA, and we have put around £60m back into the local community in spending power - a good payback."

On his own future, the man who invented the disposable lens in his back garden in Uddingston said: "I don't think I was programmed with a reverse gear... but increasingly it is only right to measure one's own contribution."