I've come out of review semi-retirement just to write this, such is the intensity of my feelings toward this show. I could waste your time (like this drama wasted mine) going on and on about how worthless, hateful, and often dull this show is, but I'll instead attempt to be brief:

Please do not watch this drama.

Watching "The Light in Your Eyes" is like settling down in front of a campfire, ready for the storyteller to begin his story, but instead, he starts spitting in your face and laughing at you while shouting "That's life, SUCKER!!" That's not storytelling, that's assault. And that's what you're basically signing up for by watching this drama.

You'll spend hours and hours watching characters be miserable, slowly start to grow and learn lessons, only for the writers to throw in a twist at the 11th hour that renders meaningless every single episode that came before. This drama takes great pains to establish rules, characters, and moments for you to become invested in, and then completely throws all of them away, amounting to nothing but wasted hours of your life. The sudden shift in the drama's direction is so jarring that I wouldn't be surprised if the writing team was completely changed halfway through. A perfect example of what I'm talking about: they literally change the main character of the show in the last episode. The first male lead actually disappears; no resolution, no ending, no future. He finishes the show as an unimportant side character who we barely know. Important plot elements set up at the beginning are, by the end, either 1) completely ignored and given no resolution/explanation, or 2) handwaved away with the laziest and most trite writing cliches in existence. It's so bad that I can't read the MDL synopsis of this show without feeling like it's nothing but a collection of lies.

I'm baffled that anything this inexcusably poor, this aggressively disrespectful to its audience, could ever make it to the airwaves. What's worse is that there are aspects of the production that are high quality. 77-year-old actress Kim Hye Ja is amazing, bringing energy and believability to her role, despite her age and the demands of a full drama shooting schedule. Kim Ga Eun portrayed a character who was rather like an island in the storm for me in this terrible drama, as almost every scene with her was great, even though most of them were completely pointless, just like every other scene in this show. Episodes 10 and 12 were fairly well done, and Ahn Nae Sang absolutely hit it out of the park in 12.
Other than those things, positive aspects to this show are very few and far between.

So again, I beg you: please, please do not watch this drama. Show yourself a little love, put it on "Not Interested", and never think about it again.