We consider the strong field asymptotics for the occurrence of zero modes of certain Weyl-Dirac operators on $\R^3$. In particular we are interested in those operators $\Dirac{B}$ for which the associated magnetic field $B$ is given by pulling back a $2$-form $\beta$ from the sphere $\sphere$ to $\R^3$ using a combination of the Hopf fibration and inverse stereographic projection. If $\int_{\sphere}\beta\neq0$ we show that
\[
\sum_{0\le t\le T}\dim\Ker\Dirac{tB}
=\frac{T^2}{8\pi^2}\,\biggl\lvert\int_{\sphere}\beta\biggr\rvert\,\int_{\sphere}\abs{\beta}+o(T^2)
\]
as $T\to+\infty$. The result relies on Erd\H{o}s and Solovej's characterisation of the spectrum of $\Dirac{tB}$ in terms of a family of Dirac operators on $\sphere$, together with information about the strong field localisation of the Aharonov-Casher zero modes of the latter.