Engineering and Technology set 3 Flashcards
What is opthalmology?
Opthalmology is the study of the eye.
What is the back of the eye called?
the fundus, that’s the spot that causes red eye on photographs.
What are the four things that are in the fundus?
the retina, the fovea, the optic disk and the macula
What causes the red eye in photos?
there are lots of blood vessels there and they reflect the light back out of the eye
How do you stop red eye on photos
don’t look directly at the camera
When is red eye worse and why?
red eye is worse when photos are taken at night because the pupil is wide open
Why does the eye dr take photos of your fundus?
To check the overall health of your eye
What is an opthalmoscope?
An opthalmoscope is the instrument the eye doctor uses to look in your eye
who invented the opthalmoscope?
Charles Babbage in 1847, and then later it was made by Helmholz
Why were 150 models of opthalmoscopes invented over 50 years?
seeing the fundus is difficult so they were trying to perfect the design.
What was the original source of light in the opthalmoscope?
candles, then oil and gas because the light bulb was not invented, nowadays they are battery operated
How does an opthalmoscope work?
light is focussed and directed into the eye, the reflected light is directed through a one way mirror into the optometrist’s eye.
what is the limitation of the ophtalmoscope?
it can only see part of the fundus at one time
What is a fundus camera
the fundus camera takes pictures and can see larger areas
What is a scanning laser opthalmoscope?
SLO uses a single wavelength of light from a laser (not a light bulb), motorized mirrors more the light, and a computer makes a 2D image
What is optical coherence tomography?
OCT takes pictures at many depths in the back of the eye and creates a 3D image, like a CT image
why do they look at the fundus?
the fundus changes depending on the disease you have.
what problems can they see on the fundus?
swelling of the retina, changes in blood vessels and nerves are signs of eye disease, changes in the shape of the optic nerve can help diagnose glaucoma (which causes blindness)
Why is it important for people with diabetes to have their fundus checked?
diabetic retinopathy happens to diabetics, but surgery can fix it if it is caught soon.
What does a person with glaucoma see?
the picture is greyed on the sides, like looking through a tunnel
What does a person with diabetic retinopathy see?
completely blurred images, can’t make out anything but blurs
What types of radiation can humans not see
we cannot see thermal (long-wave) and we cannot see infrared radiation
What does a thermal camera do?
It takes photos of the thermal/heat something gives off. Called a heat map
What element is used to make the lens of an infrared camera?
Germanium
What is a microbolometer?
it is a heat detector
How are thermal cameras used?
To detect heat loss in houses or to find people hidden by smoke during fires
what are some new uses?
using thermal cameras to find sick people at airports via their temperature
What illnesses can be found with thermal cameras?
Carpal tunnel syndrome in wrists and thyroid problems, and possibly cancer.
Why would thermal imaging be a good way to find disease?
Because it is non-invasive. You don’t have to get cut open to find the problem.
How is thermal imaging being used in Calgary?
There is an online tool where you can look at your neighbourhood and see your house, to compare your house’s heat loss to that of the neighbours. You can get a rating on your home’s energy efficiency.
