Bloomington, MN | Eye and Vision Tests Explained by Dr. Chu | Chu Vision Institute
Dr. Ralph Chu: Hi, I'm Dr. Ralph Chu. And today I'd like to talk to you about one of the tests we perform at our clinic called the refraction. The refraction is one of the most important and basic tests we perform. It's where we ask you, which is better one or two that helps us determine your level of vision. And that allows us to better counsel you about your surgical options, whether they be cataract surgery, laser vision correction surgery, corneal surgery, or even glaucoma surgery. The test starts with a device called the phoropter, which is here. And each of these dials on the device allows us to pinpoint and hone in on specific parts of a person's vision. We can determine the level of nearsightedness and farsightedness. We can determine the level of astigmatism, and we can even compare one eye versus two eyes for distance, as well as for reading.
Dr. Ralph Chu: This is a subjective test so we often repeat this test at every visit. And even if the patient has had their test done by our referring doctors, we perform the test again so we have a comparison. This helps us to determine stability of the refraction, and again helps us provide better information when we're counseling our patients about their surgical options.
Dr. Ralph Chu: Hi, I'm Dr. Ralph Chu. Today. I'd like to tell you about one of the most important tests that we perform in our clinic. It's called corneal topography. This is the corneal topographer here and what this device lets us do is see things that we can't see with the naked eye. So even though we're performing a microscopic examination of the cornea and the structures of the eye, the topography allows us to collect data much like a satellite collects data about the topography of the earth. So this device projects rings on the surface of the cornea and the computer calculates the data from the rings to give us a shape image of the eye. That allows us to better detect what type of astigmatism a patient has and whether we can help them with laser surgery or cataract surgery.
Dr. Ralph Chu: Hi, I'm Dr. Ralph Chu. And today I'd like to talk to you about one of the tests that we perform in our clinic. It's called specular microscopy. This is the specular microscope here. And what this test allows us to examine, visualize, and count are the cells on the underside of the cornea called endothelial cells. The cornea is the clear dome on the front part of the eye. It stays clear because these endothelial cells, which are located inside the eye on the underside of the cornea, help to keep the cornea clear by pumping fluid from the cornea. This is important to me as a cornea specialist because this allows us to better understand the health of the eye and to kind of counsel patients before intraocular procedures that may stress the endothelium, such as cataract surgery, corneal transplant surgery, or other interactive procedures that we perform.