Hi fullmoonlibra. its very tricky because you might see an afflicted Moon in the chart of someone with an eating disorder, but then you'll see a similar chart where the person has no problems with eating. The archetypal bare bones shown in the birth chart have to be fleshed out by difficult childhood experiences (and perhaps difficult karmic history) in order for the more difficult expressions to arise.
Most charts have some possible indication of mental illness if the early environment was conducive to that. Even a very fortunate looking chart may be of someone who has for some reason incarnated into a family that does not appreciate her/his temperament.
I personally feel its better to look at it the other way round - when someone comes along who is suffering from mental illness, you can look at the chart to see the innate sensitivities that were affected by the early environment.
Having said that, there are obviously rules of thumb around this kind of thing. Saturn, Chiron and Pluto have a greater tendency to reflect a sensitivity to wounding than other planets, and a greater tendency to resort to excessive defensiveness and controlling behaviours in response. Hard aspects are more likely to reflect difficulties, although flowing aspects can help a problem to go unchallenged. Each element has its fears (water fears isolation, air fears suffocation, earth fears chaos and fire fears lack of meaning) so for example Moon opposite Uranus in a watery chart with Moon in Pisces will be a lot harder to bare than Moon opposite Uranus in an airy chart with Moon in Gemini.
The water houses tend to be more problematic as they often reflect hidden family dynamics that have not been dealt with consciously and therefore can wound the vulnerable child in some way.
Something like blindness is very tricky to, because blindness for one person may be life-destroying, and for another a springboard to a new and fulfilling way of life. And I suspect that sometimes the chart will be similar in both cases - perhaps hard aspects to Chiron. Whereas maybe Chiron making easier aspects may not hit so hard, but the disability may be too easily accepted and apathy may set in. The guy over the road from me has one leg and never goes anywhere or does anything. But I've seen people with one leg bombing up and down the swimming pool, having jogged or cycled to the sports centre. I think its these differences of attitude that the chart can show rather than whether or not someone is, or is more likely to become, disabled.
I think that Neptune is worth looking at with regard to how someone copes with illness of any kind, due to its tendency to potentially play the victim and feel helpless.
Don't know if this is any help, but its just some thoughts..