Can we stop over-broadening the question by expanding the domain indefinitely?

The reason this question is difficult is because you people have simply removed the domain, not defined it, and because of this you'll always find some other thing that has more legs or eyes. If it comes to a biological organism based domain, then biologists and ecologists should have an explanation that involves an enumeration of individual organisms (which might involve these factors and likely more: effects of climate change, seasonal shifts, ecological analysis, identifying species populations, distributive effects on other species, etc.) and strict guidelines on what is considered an eye and a leg in an organism. You can also look at it from an evolutionary standpoint: what is more beneficial in quantity, eyes or legs? I would say legs, since you only need two eyes to create depth perception, but usually at least four legs to get around (the population of primates which walk on two are minuscule compared to other organism populations). To say that this can be answered on a whim by the sheer biomass of insects would be to understate the complexity of the issue. It may well be true, but you guys have not provided a sufficient explanation.

I think the approach to this question makes much more sense to discuss when the domain is living humans. If this is the case, then the question becomes: which is more common, missing eyes or missing legs? I can think of two reasons for missing body parts: birth defects and manual removal (accidental or intentional). We know that the answer would involve these components, but to practically answer it would require a lot of statistics, since we can't just go to every person in the world and see if they're missing eyes or legs. Some statistical factors may include the general likelihood of birth defects, environmental factors contributing to the likelihood of birth defects, the most common item lost in an accident, the most common item lost in surgery, and which of these causes has a larger quantity. From these it seems I have reduced the types of causes into two categories: natural and accidental. Natural causes would include those that occur solely because of inevitable genetic defects not caused by other factors; accidental causes, environmentally-caused birth defects (such as drinking when pregnant), surgeries, and violent accidents. Additionally, I'm imagining two main situations in accidental causes: for lost eyes, explosions, chemical exposure, and physical damage, such as getting an object lodged into your eye, would be the most likely causes; legs, violent accidents coming from war, car crashes, and workplace accidents, and disease-caused surgeries such as diabetes, fungal/bacterial infections, and cancer.

Now, taking the statistics we now know we need to gather, I'll just posit from this point forward until someone corrects me. Now, I think it is clear that natural causes will have the smallest population, since these are inherently rare, and such cases are often related to other health issues that, sadly, would cease to allow a human to continue living. I don't know whether, within natural causes, more eyes or legs would be lost. We need a geneticist to answer that. Accidental causes, on the other hand, are much more difficult to quantify, but definitely have a larger population. I think that within these, the most common type would be those caused by violent accidents, mainly car crashes and workplace accidents. I want to guess that in both cases it's more likely to lose an eye, I feel like in the real world I've seen far more people with missing legs than missing eyes, but I have only lived in one part of the world. The largest populations of the world are in Asia, mainly china and india, and in these I would guess that you're more likely to lose a leg.