Exam Room 101
Have you ever wondered what the eye spoon is technically called? How about that big pair of glasses that holds the lenses we flip back and forth? Whether you are visiting the office for your annual exam, pink eye, or floaters, you can be sure we are utilizing several of these tools.
Some jokesters like to call it an eye spoon, but it is really called an occluder because it is used to “occlude” or block your eye. When checking vision, it is important to isolate each eye individually. If there is a vision problem with one of the eyes, it can sometimes be overlooked by the patient because the good eye compensates or takes over for the weaker eye.
If the measured vision is not normal, you might be handed this holey occluder to cover the weaker eye. While looking through the ideal 1.2 mm pinhole size, the amount of extra light rays is greatly decreased. This allows a more precise amount of focused light to land on the retina, leading to a clearer image. The pinhole occluder minimizes the effects of refractive error, corneal conditions, and cataracts on vision. The resulting measurement provides an idea of the patient’s best potential vision. Despite what the unreliable internet might suggest, it is not recommended to wear glasses that contain pinholes due to safety reasons.
This glorified flashlight has several different purposes. Extraocular muscles, the muscles that keep the eyes aligned and in unity, are tested for smoothness and extent of movement while looking at a moving transilluminator. The pupils are also examined with the transilluminator for size, shape, reactivity to light and comparison with the fellow eye.
This handheld device measures eye pressure without the need for drops or a puff of air. Measuring the eye pressure is an important component of the exam because it is one of the main screening tools for glaucoma. Normal eye pressure is between 10 to 21 mmHg (millimeters of mercury – unit of measurement), however, it is very possible for an individual to have an eye pressure of 9 mmHg or 22 mmHg and still be “normal”. Eye pressure is a recordable value that is compared each visit to determine if there is an increased risk of glaucoma.
Snellen Eye Chart
The Snellen Eye Chart is most commonly used to measure visual acuity. While most people are accustomed to having the “Big E” at the top of the chart, digital versions of the eye chart allow us to change the letters to keep you on your toes. We can even use numbers or shapes for younger children. The digital chart also has additional tools, such as short animated clips, to give kids something to look at during specific parts of the exam. If the patient is non-verbal or too young to read the eye chart, there are other methods of determining a glasses prescription (see below).
You might wonder how reliable a child answers to “Which is better? 1 or 2?” Fortunately for us, we have a tool, called a retinoscope. Using this instrument, we are able to determine an exact glasses prescription without any subjective response from the patient. This is extremely useful when examining infants and young children.
The phoropter (“for-op-ter”) contains many different lenses that the doctor shows the patient to see if there is an improvement in vision with varying combinations of lenses. The refraction is the part of the exam that uses this instrument. Some patients worry they will say the wrong thing during the refraction, but fortunately, the doctor can sometimes steer you back in the right direction if the responses are not making sense.
The slit lamp has many different functions, making it one of the most versatile and useful tools in the exam room. It is a light source with several levels of magnification, which can also be used with a handheld magnifying lens for even more detailed viewing. The health of the entire eye (front, middle, and back) can be examined with a slit lamp. Eye pressure can also be measured with the slit lamp using a technique called Goldmann tonometry. This method is the standard of care for patients with glaucoma.
Binocular Indirect Ophthalmoscope (BIO)
Before the virtual reality boom, we were told this looked like a coal miner’s headlamp. Now, the kids like to think of it as a VR set that transports us to another realm of eye care. The BIO provides enlarged views of the retina with the help of a handheld magnifying lens. In order to see the full extent of the retina, the pupils need to be dilated. A dilated retinal examination using the BIO can detect conditions, such as retinal detachment, diabetic retinopathy, and macular degeneration.
There will be a 10 questions quiz at the start of your next eye exam, so be sure to study these ocular instruments. Just kidding, but we hope you learned something new!