I have searched the Census for your Robert Kelly.

Baptism.
Name: Robert Kelly.
Baptism Date: 30 Dec 1860.
Baptism Place: Michael, Isle of Man.
Residence: Village.
Biography: Parent: Elizabeth Kelly (illegitimate).

1861 Census.
Catherine Kelly 69.
Eleanor Callin 25.
John Callin 21.
Henry Kelly 3.
Robert K Mills 3 Months.

On the 1871 Census, this maybe your Robert Kelly - written as Killey.

1871 Census.
Name: Robert Killey.
Age in 1871: 9.
Estimated birth year: abt 1862.
Relation: Patient.
Gender: Male.
Where born: Braddan, Isle of Man, Isle of Man.
Civil Parish: Conchan.
Town: Douglas.
County/Island: Isle of Man.
Country: Isle of Man.

It doesn't state his illness, maybe a search of the Hospital records (if available) could say this.

OR, if your Robert Kelly was working in the mines at the age of 9yrs. could he have been blinded at an early age ?

Could a search of the Newspapers - by Gem.

Maybe find a report of a Mine accident in 1871.

This fits in with him learning the Trade of Basket Maker in 1881 Census.

I sure hope this helps.

Averil