Novartis has revealed how much it paid to buy Encore Vision, a Fort Worth startup that has developed an eyedrop to treat presbyopia — and it’s an eye-opener.

In an SEC filing Wednesday, the Swiss pharmaceutical giant that owns Alcon put the preliminary fair value of the transaction announced last month at $465 million. Novartis reported that the deal includes an initial cash payment of $375 million “before ordinary purcahse price adjustments,” plus $90 million due Encore shareholders over time “upon achievement of specified development and commercialization milestones.”

Big winners in Novartis AG’s acquisition of Encore Vision for $465 million are members of a network of angel investors in Fort Worth, TX, that bet $4 million on the presbyopia-correcting eye drop that Encore Vision president and CEO Bill Burns has been working on for about nine years…

Fort Worth-based eye care firm Encore Vision Inc. is being acquired by Swiss drugmaker Novartis, the company announced today.

Encore Vision has developed a topical treatment for presbyopia patients, or people with far-sightedness. It is estimated that more than 80 percent of adults over the age of 45 develop presbyopia.

According to a Novartis news release, the acquisition adds a first-in-class disease modifying topical treatment for presbyopia to the Novartis ophthalmology pipeline. Encore Vision’s product provides “a potentially disruptive innovation to patients in a new therapeutic area of high unmet need and high prevalence.”