<s>
A	O
Shack	B-Algorithm
–	I-Algorithm
Hartmann	I-Algorithm
(	O
or	O
Hartmann	O
–	O
Shack	O
)	O
wavefront	O
sensor	O
(	O
SHWFS	O
)	O
is	O
an	O
optical	O
instrument	O
used	O
for	O
characterizing	O
an	O
imaging	O
system	O
.	O
</s>
<s>
Each	O
is	O
focused	O
onto	O
a	O
photon	O
sensor	O
(	O
typically	O
a	O
CCD	B-Algorithm
array	I-Algorithm
or	O
CMOS	B-Device
array	O
or	O
quad-cell	O
)	O
.	O
</s>
<s>
Since	O
only	O
tilts	O
are	O
measured	O
the	O
Shack	B-Algorithm
–	I-Algorithm
Hartmann	I-Algorithm
cannot	O
detect	O
discontinuous	O
steps	O
in	O
the	O
wavefront	O
.	O
</s>
<s>
Shack	B-Algorithm
–	I-Algorithm
Hartmann	I-Algorithm
sensors	O
are	O
used	O
in	O
astronomy	O
to	O
measure	O
telescopes	O
and	O
in	O
medicine	O
to	O
characterize	O
eyes	O
for	O
corneal	O
treatment	O
of	O
complex	O
refractive	O
errors	O
.	O
</s>
<s>
developed	O
and	O
patented	O
an	O
inverse	O
of	O
the	O
Shack	B-Algorithm
–	I-Algorithm
Hartmann	I-Algorithm
system	O
to	O
measure	O
one	O
's	O
eye	O
lens	O
aberrations	O
.	O
</s>
<s>
While	O
Shack	B-Algorithm
–	I-Algorithm
Hartmann	I-Algorithm
sensors	O
measure	O
the	O
localized	O
slope	O
of	O
the	O
wavefront	O
error	O
using	O
spot	O
displacement	O
in	O
the	O
sensor	O
plane	O
,	O
Pamplona	O
et	O
al	O
.	O
</s>
