6 essential factors to consider when choosing optometric loupes
Surgical loupes are designed to allow you to see better and bolster the quality of your work. The right surgical loupes will serve as an unnoticeable extension of your abilities without actually interfering. Surgical loupes will empower you to work more effectively as well as more ergonomically in comfort.
In order to achieve these types of benefits, it's up to you to choose the right type of surgical loupes. Use the following information to help you select the best loupe for your needs and application.
The magnification of the loupes determines the size images will appear. In most instances, magnification is a highly personal choice. Loupes with a high magnification will provide a larger image, but it also means a reduced depth of field and view.
In most instances, residents in training, or simple surgical cases can get by with a 3.0x or 2.5x magnification. If you have a more complicated or delicate procedure, you may be best suited to choose either a 4.5x or 3.5x magnification factor.
Choose a magnification factor of 5.0x if you are conducting a microsurgery or are working on a very tiny area. You can substitute higher magnification loupes in the place of a surgical microscope.
2. Field of View
When you look through surgical loupes, the area in focus is called the field of view. The field of view increases the longer the working distance of the loupe. At the same time, lower magnification factors provide a larger field of view.
You must carefully consider this tradeoff when choosing surgical loupes. If you are using a Galilean loupe, the center of the image may be exceptionally clear, but the outside rim of the image may be blurred. With a prismatic loupe, the image tends to be sharper to the very edge of the field of view.
Resolution dictates the visibility of details. The coatings and types of glass used in the lenses can have a great effect on the loupe's resolution. You can test a set of loupes by viewing them through graph paper.
Make sure to pay attention to curvature or distortions of the lines. Higher resolution equipment will offer straighter, crisper lines. On the other hand, the lines viewed through lower resolution lenses will be curved and slightly blurred.
4. Depth of Field
Similar to the field of view, the depth of the field is directly related to the magnification factor and the working distance. The depth of field is defined as the in-focus depth when peering through the loupe.
In virtually all instances, greater depth of field is preferred because you're able to see deeper into the subject without having to reposition. For the best depth of field, you should choose a loupe with a lower magnification factor or a longer working distance.
5. Working Distance
The distance at which the loupe will focus is known as the working distance, which must be equal to the distance from the top of the subject to the loupe lense. Every loupe has a predefined working distance, but the distance you will require hinges on the table height, sitting vs standing, your posture, as well as your height.
It's best to discover your optimum working distance, and choose a set of surgical loupes that satisfies your criteria. For a rough idea, you can measure your working distance. To do so, simply stand or sit in a comfortable position with your back erect. Make sure to avoid leaning forward too much, and then measure the distance from the top of the subject to your eyes for a relatively rough idea.
6. Interpupillary Distance
The interpupillary distance is the distance between the pupils of your two eyes. Your loupes should provide a comfortable fit based on your eyes. For an exact measurement, check with your optometrist or optician. While many optometric loupes are adjustable, you should always choose loupes that are set to the proper interpupillary distance for you.
How to Choose the Best Surgical Loupes
In general, you should choose the lowest possible magnification for your needs. It's simple: the lower the magnification, the greater your field of vision and depth of field. At the same time, the longer the working distance, the greater the field of view.
With a larger field of view, you can turn your head a lot less, which reduces eye fatigue and eye strain. You should also pay special attention to the fit of your optometric loupes as well as the weight. In most instances, lighter loupes offer more comfort for extended periods of use and are less likely to slide down the bridge of your nose.
Contact Keeler Ophthalmic Instruments
At Keeler Ophthalmic Instruments, we offer a wide array of surgical loupes. Best of all, we have the experience and expertise to help you choose the best equipment for your application and personal preferences.
Contact Keeler Ophthalmic Instruments today.