I always love learning a bit more about Discus. What are you basing the fact that this guy/girl might be stunted on? Is it the eye or just the overall shape (lack of roundness so to say)?
I'm not necessarily agreeing or disagreeing with whether or not its stunted but just trying to learn how to tell for sure.
It can be a little tricky to tell whether a discus is stunted or not. (Or if it's a runt). In addition to the size of the eye (appears larger than it should be in relationship to the overall body size) and it's position (very near the forehead), as well as the body shape ( slightly football-shaped as opposed to nearly round.
From forehead to chin, there should be enough room (body space) to vertically insert 5, 6, or 7 eyes. If it's less than 5, that also is another sign of being stunted.
The continuing presence of stress bars too, is somewhat of a give-away, along with poor coloration over several months, for whatever strain it is.
These are all strong signs it's stunted.
The concluding factor though, is it's age, if known.
A properly grown out discus usually reaches nearly 3" after around 3 months (approx. 1" per month growth) followed by slower growth of 1/2" to 3/4" in the next few months. By 6 or 7 months, it should be around 5" or so.
If the discus remains at around 3" in its 5th, 6th, or 7th month, and continues to exhibit the other traits mentioned earlier, then you can be more or less certain it's stunted.
BTW, a stunted discus is one that turns out that way due to the being grown out in less than ideal water quality and conditions, whereas a runt (like pups) are genetically disposed to remain very small from birth.
Hope this helps.