Gabby41: welcome to the forum.
Here's the best advice I was ever given about dealing with keratoconus: Don't Panic!
How old is your son?
Did I understand you right to have said that your son was told that he needed cross linking at the same consultation as his condition was diagnosed? If that is what happened then he has a perfect right to ask for a consultation with another specialist.
Crosslinking is a relatively new procedure; the old standard 'first response' was to fit contact lenses when the patient's KC got to the point where glasses were no longer capable of providing the necessary correction. Crosslinking aims at achieving two ends. Firstly it can slow the progression of the condition and secondly it can provide a better eye surface for a contact lens to be fitted. If your son had only been diagnosed I don't really understand how it was apparent to the consultant that his condition was progressing and might benefit from cross linking.
There are one or two additional things that you may like to know:
The majority of people with keratoconus will never need any surgical intervention at all.
Most people live happily with a regime of contact lens wear.
Some people with KC never need even contact lenses as their sight can be corrected with glasses alone.
If the time comes when your son needs more radical interventions then there are several stages to this progression:
Little 'crescent shaped' clear plastic strips can be inserted into the cornea to improve its shape.
there is Crosslinking
There are lenses fitted inside the eye
There is the cornea graft (transplanted tissue from a donor)
Every good wish
Andrew