Brian Barsky is not like most people who suffer
from vision problems—stuck living with what their doctor prescribes
or picking from a narrow set of options.
As a professor of computer science, optometry and vision science
at UC Berkeley, he has taken matters into his own hands when it
comes to treating an eye disorder from which he suffers.
Called keratoconus, the condition is characterized by bulges in
the eye that occur where the cornea is too thin.
To illustrate how a thin area causes a bulge rather than a dent,
Barsky used the analogy of a balloon bulging out from pressure in an
area where its skin is thinner.
The effects of keratoconus are somewhat like those of
nearsightedness, but with a faint double image.
"One of the problems I've observed is that if I look at the edge
of an object, I might see two edges," Barsky said.
Glasses and standard contact lenses, which rely on a spherical
eye surface, do not deal well with keratoconus, and it is often
difficult and time consuming for doctors to find lenses for a
patient with the condition.
To alleviate these problems, Barsky created computer simulations
of vision, both with normal and defective eyes, using measurements
from real patients.
"We're successful the vast majority of the time, but when
someone's keratoconus becomes more advanced, it becomes more
difficult to find a contact lens that fits them," said clinical
optometry professor Michael Harris. "Barsky's custom lenses help
solve that problem."
These artificial images Barsky has created can help doctors see
what their patients see, and better treat them.
They can also be used to visualize the results of a successful
surgical operation ahead of time.
Barsky applied his background in computer science to the design
of contact lenses to help his own keratoconus.
By using a type of mathematical curve called a spline, he
distilled the irregularity in a karatoconus-afflicted eyes down to a
few equations.
"The salient feature of splines is that, rather than trying to
find a single equation to describe the entire curve or surface, they
break it into smaller pieces and define an equation to describe each
of the pieces," Barsky said.
In order to measure the cornea so that he could fit contacts to
it though, the measurement tools needed to be refined.
Physicians typically use a machine called a corneal topography
device to measure the cornea and determine its shape.
Unsatisfied with the inadequacies of existing devices, Barsky and
his collaborators took the raw data from the device, before it had
done its own calculations, and manipulated the data themselves, so
the direction in which the eye was looking would not matter.
With this precise data, doctors can create contact lenses
custom-fit to a patient's eyes.
Since keratoconus involves a thinning of the cornea, procedures
like Lasik surgery, which correct vision by carving away pieces of
the cornea with a laser, may be inadvisable.
"One of the applications of the measurement is to detect if a
person has keratoconus, to suggest that they should not get Lasik
surgery," Barsky said.
These techniques may also show up in Holllywood—they could be
used for making computer-generated scenes closer to those captured
by real cameras and eyes, Barsky said.
"I think it's a very interesting and innovative approach to
solving a problem that affect the vision of a significant number of
people," Harris said.
