Though Corning (NYSE:GLW) stock has returned an impressive 18% so far this year, those gains haven't come easily. In fact, just before  Corning's solid quarterly earnings report a few week ago, shareholders were even sitting on a slight year-to-date loss, and even now, Corning stock sits around 5% below its 52-week high set in July.

But despite Corning stock's short-term volatility, there's still plenty to like about shares of the specialty glass maker when you look at them through a long-term lens. Here are three reasons patient investors might consider buying Corning stock today.

1. TVs are only getting bigger
Last quarter, a whopping $1.1 billion of Corning's revenue -- or 41.5% of its total -- came from its core Display Technologies segment. Of that amount, the vast majority is from LCD television glass sales. In short, this means Corning's overall results are significantly affected by both the price and volume of LCD glass it sells.

Corning stock

A Corning scientist inspects a panel of glass. Source: Corning.

On the former, Corning has suffered for the past several quarters amid consistently falling LCD glass prices. Though it's worth noting those price declines have moderated and are expected to continue to do so going forward.

But more importantly, as prices continue to stabilize, Corning last month raised its guidance for the global retail LCD glass market to increase 10% for the full year 2014, compared to its previous outlook for a mid- to high-single-digit increase. The reason? Consumers are not only buying more TVs at retail than before, but more of those purchases as a percentage of the total are of increasingly affordable ultra-high-definition sets, which tend to be of larger than average size.

As a result, Corning management now expects average screen sizes to increase 3% through 2015, and believes screen size growth beyond that will be "robust." If that turns out to be the case, it's great news for Corning stock investors.

2. Ambitious plans for Gorilla Glass
On Nov. 20, Corning officially unveiled Gorilla Glass 4, the latest in its innovative line of protective cover glass. But that itself wasn't a big surprise, as Corning had told investors of the announcement well in advance.

What we did learn, however, is that Gorilla Glass 4 was built specifically to address smartphone users' most prominent concern: durability when devices are dropped on rough surfaces like streets, sidewalks, and parking lots. In fact, Corning says Gorilla Glass 4 withstood such drops in lab tests up to twice as well as competitive glass designs.

And while Corning unsurprisingly didn't call out its current Gorilla Glass 3 product among those "competitors" in the Gorilla Glass 4 press release, it did provide these interesting images on comparative check depth and abrasion levels in the official Gorilla Glass 4 data sheet:

Corning Gorilla Glass Comparison

Source: Corning.

Consequently, in addition to that improved damage resistance, this also enables a thickness reduction and, in turn, thinner devices. Specifically, device manufacturers can order Gorilla Glass 4 sheets as thin as 0.4 mm, compared to the minimum thickness of 0.55 mm for Gorilla Glass 3.

What's more -- and keeping in mind Corning will almost certainly continue to improve Gorilla Glass from here -- Corning also announced in early November its intention of expanding its presence in South Korea with the new Corning Technology Center in Asan. According to a subsequent report from BusinessKorea, the R&D center will receive annual investments from Corning of around 10 billion won ($9.3 million) upon completion, and will employ 20 to 30 full-time researchers. In addition, BusinessKorea says Corning is investing 900 billion won (or around $832 million) to bolster its production lines in the country, with the aim of increasing Gorilla Glass production volume by at least fivefold by 2018. 

Investors should be excited that this generally conservative company has such high expectations for its already lucrative cover glass business.

3. Methodical capital returns
Finally, long-term investors can look forward to Corning's consistent shareholder-friendly stance on capital returns.

Over the last three years, for example, Corning has spent $5.5 billion on share repurchases, including $200 million spent to repurchase and retire 9.6 million shares last quarter alone. And that's in addition to its regular $0.10 per share quarterly dividend, which currently generates an annual yield of 1.9%.

What's more, in anticipation of the conclusion of its current share repurchase authorization in the current quarter, Corning's board of directors has agreed to accelerate the consideration of future repurchases. Investors should keep their eyes open, then, for an announcement on how Corning intends to continue using its free cash flow to further reward patient shareholders. 

Steve Symington has no position in any stocks mentioned. The Motley Fool recommends Corning. The Motley Fool owns shares of Corning. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.