Originally Posted by Soul
The supplements you mention, fish oil and vitamin D3 along with K2, might be of help with eyes. I've read a few times now that low carbohydrate diets can be helpful also with eye sight. One article that you might find helpful.
"The Modern Assault on Eyesight"
Low-carb diets, in general, may provide some benefits as well as health disadvantages. I'm not sure that a longer-term state of ketosis from a low-carb diet is actually healthy. The Primal diet mentioned here appears to be another name (or a variation) of the Paleo diet. Some experts rate the modern versions of the caveman diet very low with regards to health concerns.
For athletes who burn a lot of calories, I would suggest more carbs, not less. We should also be careful about what we mean by a low-carb diet. Fruits and vegetables are primarily carbs. Lycopene, lutein and the other eye nutrients (e.g. carotenoids) are derived primarily from fruits and veggies.
With regards to carbs, what should be avoided is foods with added
sugars and carbs that are highly processed (like white bread). The intake of carbs with a high glycemic load (and high glycemic index) should be minimized, especially when snacking. In the context of a well-balanced meal, some intake of these carbs is probably ok. However, one should not consume large quantities of these high glycemic foods -- sugary and high-glycemic snacks should be kept to a minimum. We should avoids "bad" carbs, not all carbs.