At present, and for the distant forseeable future, it is too hazardous on any large scale.

When the human genome was tallied, the results came out to less than 40,000 genes, which was one hell of a lot fewer than estimates of up to 100,000. This is about twice what a fruit fly has, and only about 300 more than a mouse.

Now, I'm no expert in this field, but the immediate conclusion is that a lot more information is being packed into this system than can be explained by the simple binary-type linear codes one thinks about when imagining a DNA molecule.

The fact is, the human genome is the result of billions of years of haphazard evolution, "random selection," and to be frank, it's what they call a kludge. Evolution doesn't go for elegance, or simplicity, or beauty. It goes for what works right now, and if some of the genome is garbage, some leftovers, and some held together with duct tape, Mother Nature couldn't care less.

So it is likely that more information is stored in seemingly unrelated parts of the genome, or maybe even in the overall pattern of how unrelated genes are arranged. Maybe in something that nobody understands.

In any case, removing the gene for nearsightedness may result in an unforseen change in a completely different system.

An example: some people think that homosexuality has a genetic factor, and there are those who think that homosexuality could be simply eliminated by genetic engineering or selection. Again, aside from the homophobia, this is the result of misplaced digital/linear thinking.

At the very least, one should immediately wonder why a gene pattern that almost by definition would tend to breed itself out of a species, is still active after millions of years. The most obvious answer is that the gene is connected to something more important to survival than reproduction, which would have to be something very important indeed. What it would be I have no idea, but I would seriously be against messing with it. (The other answer is that homosexuality is a relatively recent mutation, which is a fascinating idea, but not likely.)

Research genetic engineering? Of course. Treat individuals with severe genetic problems? Sure. Carefully.

But I would be highly opposed to trying to impose some "beneficial" genetic engineering on any large scale, which is the definition of eugenics.