Introduction
Binoculars, open- field auto ref/Keratometer, and conventional Autorefracto are all visual diagnostic devices (Wan et al., 2012). All these devices operate on basic principles, which involve refraction of light. What this means is that the instruments use light to carry out a diagnosis of the patient. Wan et al. (2012) are of the view that the functioning of the devices is basically the same. However, different modifications and features are used to support the capabilities of each and every device. The devices are used in various fields.
The fields within which they are applied include, among others, military operations, site seeing, and medicine. To achieve these varying functionalities, the devices come in varying sizes. In addition, different devices have different magnification strengths. Moreover, technological applications vary from one device to the other. One of the major aims of the varying features is to improve the quality of the images produced. High-quality images provide the practitioner with more details regarding the object under scrutiny compared to a low-quality image.
Glass prisms are used to form images in the devices. The prisms refract the light at the set angles to produce the desired results in terms of the quality of the image. The quality of the image is altered by changing the angle of the glass prisms. Alignment of these glass prisms is vital in imaging. According to Koeppl et al. (2005), the arrangement of the glass prisms in the device determines the path taken by the refracted beam of light.
As a result, the arrangement has a bearing on the quality of the images generated. There are additional features used to improve the quality of the images produced by the devices. The additional features may include, among others, the use of anti-reflective coating on the device’s inner surface (Gupta et al., 2008).
In this paper, the author seeks to analyze the various similarities and differences between the three devices used in this field. The three include the binoculars, open- field auto ref/Keratometer, and the conventional Autorefracto. The writer seeks to explore the different features and functionalities of the devices. The similarities and differences between the various features are critically analyzed in the paper.
In addition, the writer will address the various physical and technological properties of the devices. Special attention is given to the technology employed in designing different devices. Moreover, the author points out the various applications of the three devices in real-time imaging. Finally, the advantages and disadvantages associated with the use of the different devices are highlighted.
Literature Review
Binoculars
Binoculars also referred to as field glasses (Gupta et al., 2008), involves the use of two similar telescopes. The two telescopes are arranged facing one direction. The use of two telescopes in the binoculars implies that the user is required to use both eyes, especially when viewing distant objects. The images generated by the device are three dimensional.
Binoculars are designed to effectively address the specific purposes they are intended to fulfill. For example, the binoculars used by bird watchers are different from those used in surveillance. The ones designed for surveillance may be more discreet in shape and size than those designed for bird watching and other leisure activities.
The different designs of the binoculars intended for different uses call for a modification of the optical parameters. The optical parameters of binoculars are vital as they determine the quality of the image produced (Wolffsohn et al., 2002). To achieve the binoculars’ desired outcomes, the designer is required to take into consideration the quality of the lenses used. In addition, the designer is expected to take into consideration the arrangement of the lenses inside the telescopes. There are other major considerations that should be made in designing binoculars. The considerations include, among others, the desired level of magnification, the field of view, eye relief, and the focus distance. The combination of these aspects significantly affects the quality and functionality of the binoculars.
The system or technology used in the manufacture of binoculars involves variations and adjustments in the distance between the object and the ocular lenses. The major aim of this adjustment is to achieve the desired focus and image resolution (Glasser, 2008). The arrangement of the two telescopes in the system gives rise to two forms of focus. The two are independent and central focus (Glasser, 2008). In independent focusing, the viewer adjusts each of the lenses used in the eyepiece differently.
The aim of this adjustment is to acquire two different focuses from each of the telescopes in the binoculars’ system. On the other hand, the central focus arrangement requires the viewer to use a common adjustment wheel in adjusting the image. The common adjustment wheel is normally located at the center of the binoculars’ system. The central location ensures that the two telescopes in the system provide a common focus. As a result of this form of adjustment, the images formed on the two telescopes are identical.
The ability of the device to achieve two different focuses means that the binoculars system is significantly different from other visual diagnostic devices. However, it is important to note that not all binoculars systems are able to achieve two different focuses. It is a fact beyond doubt that complex and advanced binoculars can change the focus of the image generated. However, other binoculars have a fixed focus.
When designing binoculars, developers apply visual technologies to improve the quality of the images obtained from the devices. Stability of the image is one of the major factors taken into consideration in designing binoculars. Stabilization of the device and the resulting image helps in reducing the shaking effect. The shaking effect is brought about by the use of high magnification in the system (Wan et al., 2012). Image stabilization is one of the factors taken into considerations when users are purchasing binoculars.
Different visual diagnostic fields require different image stabilization parameters. However, image stabilization has various drawbacks affecting the functionality of the device. For example, image stabilization may interfere with the clarity of the images produced. As a result, the device generates low-quality images compared to a device without image stabilization features. In addition to this, binoculars fitted with image stabilization technology are more expensive compared to devices that are not fitted with the technology.
The two telescopes used in binoculars produce one circular image. However, it is important to note that at times, the telescopes may produce two varying images. Two varying images may be generated if the device is unable to align them parallel to each other. The production of two images hinders the ability of the viewer to attain the desired outcomes. For example, vague images may make the viewer feel uncomfortable. The sense of unease is significant considering that the viewer has to strain in efforts to focus and match the two varying images. To address this issue, professionals may be availed to help the viewer in aligning the images parallel to each other.
In addition to image stabilization technology, there are features integrated into the design of binoculars. One of them is the use of anti- reflexive coats on the walls of the binoculars. The use of this coat helps in reducing the loss of light as a result of reflection. Moreover, the coat improves the quality of the images generated. The quality of the images is enhanced as a result of the adequate transmission of light through the telescopes.
The binoculars should be handled with a lot of care. The major aim of careful handling is to prevent the breakage or misalignment of the device’s inner components. If the device is not handled carefully, inner components, such as the glass prisms used in refracting the light, maybe destroyed or misaligned. When this happens, the functionality of the device as far as visual diagnosis is concerned is negatively affected.
Keratometer
The Keratometer is a visual diagnostic device that is capable of analyzing multiple focal spots, especially in eye care. Most of the times, a Keratometer is used in measuring the curvature of the cornea (Gutmark & Guyton, 2010). Modern Keratometer devices are computerized to improve their calculation capabilities. The design of the device incorporates some of the most recent and most advanced systems in visual technology.
For example, modern Keratometer devices incorporate the Hartmann- shack wavefront technology (Gutmark & Guyton, 2010). Use of advanced technology in designing the device improves the measurement and detection of errors in light refraction. According to Gutmark & Guyton (2010), a map or graph showing refractions of light in the eye is generated from the device. The map helps the practitioner in diagnosing and managing problems related to the eyes.
The Keratometer uses an array of microlenses to analyze many focal spots (Koeppl et al., 2005). The device is mostly used in health facilities to determine the visual status of the patient. In addition, using the Keratometer helps the observer in measuring the diameter of the field under view. The ability to measure the diameter of the field of view is supported by the device’s capability to freeze images. In medicine, this capability is of great importance since it helps in determining key details crucial to diagnosis. It helps in highlighting such details as the diameter of the patient’s pupil, cornea, and the eyeball.
Images produced by Keratometer are three- dimensional. Wave-front sensors are used to achieve three-dimensional imaging. The device helps the practitioner in detecting problems affecting the sight of the patient. When this is done, adequate measures are put in place to correct the problem on time.
In addition, Keratometer is used to analyze a fixed object. However, the image generated in such instances is manipulated to help the viewer obtain the desired information from the object under analysis. In medicine, Keratometer is used in measuring the curvature of the cornea from many meridians. As a result of this functionality, the device helps in determining the most appropriate collective measure to address the problem identified (Gutmark & Guyton, 2010).
Conventional Autorefracto
According to Koeppl et al. (2005), conventional Autorefracto is a visual diagnostic device used in medical and scientific screening and research. The device is mostly used in measuring the diameter of the pupils in patients complaining of experiencing problems related to their vision (Koeppl et al., 2005). It is a fact beyond doubt that the device excels in the execution of its intended functions. However, Koeppl et al. (2005) note that the device is inferior to the Keratometer discussed above. In addition, conventional autorefracto is inferior to binoculars, which produce high-quality hyperopic images.
The conventional Autorefracto device uses liquid crystal display screens in imaging. The liquid crystal display screen helps the viewer to observe and analyze the images generated by the device. The screens are colored to improve the quality of the images generated. Rotary prisms are used in the device to maximize their accuracy. Rotary prisms improve the accuracy of the image given that they have improved light refraction capabilities (Glasser, 2008). In addition, the application of the rotary prisms in the device improves the accuracy of measuring the small pupil’s radii.
Like the binoculars, the conventional Autorefracto device integrates stabilization technology. The technology helps in eliminating or reducing the shaking effect, which affects the quality of the images produced. However, it is important to note that stabilization technology interferes with the clarity and quality of the images generated.
The clarity in the images generated by the conventional Autorefracto device helps medical practitioners in making decisions based on the facts displayed in the images. It is noted that high-quality images capture more details about the eye compared to low-quality images (Gupta et al., 2008). Appropriate correctional measures are put in place if the practitioner using the device believes that the patient has certain abnormalities.
A Comparison Between Binoculars, Open- Field Auto Ref/Keratometer, and Conventional Autorefracto
The binoculars, the Keratometer, and the conventional Autorefracto are all visual diagnostic devices. The basic functions of the three devices are similar. However, different technologies and features are used in each of the devices to enhance their functioning. The technologies used and the resulting features are some of the differences between the three devices.
The three devices come in different designs and sizes since they are designed to perform different functions in different settings (Glasser, 2008). For example, the function of binoculars is different from that of the Keratometer. The difference in designs is aimed at accommodating the varying uses of the devices. In addition, a number of differences and similarities exist between the three devices in terms of the components used and the functioning of the devices.
One of the major similarities between the three is that they are all visual diagnostic devices, as already mentioned earlier. The three devices are used to magnify objects that are viewed. Their ability to magnify objects is crucial given that it enables the viewer to analyze the details of such an object. The devices are used in medicine to detect abnormalities in the eyes.
They detect abnormalities that cause problems related to the vision of the patient. Another major similarity between the devices is that they use principles of light refraction in their functioning (Koeppl et al., 2005). Light from the object under observation is refracted at specified angles to generate the desired image.
The binoculars, the Keratometer, and the conventional Autorefracto devices generate three- dimensional images. The ability to generate three- dimensional images is vital in medical real-time imaging. The problem diagnosed is clearly displayed in the images produced, making it possible for the viewer to make appropriate decisions in addressing the detected problems. In addition, the devices are capable of altering the magnification of the image produced. The alteration enhances the details of the object under scrutiny, such as the eye (Gupta et al., 2008).
Furthermore, the three devices use glass prisms. The glass prisms are useful in refracting light. Light from the object under examination is passed through the prisms, and the resulting images are detected from the user- end of the device. The alignment of the prisms determines the quality of the images generated.
Prisms are advantageous when used in visual diagnostic devices since they do not reflect light as it travels through the glass. In addition, smooth prisms ensure that the beams of light are not lost or dispersed (Gutmark & Guyton, 2010). As a result of this capability, prisms are vital in improving the clarity of the image generated. Furthermore, prisms are durable, which increases the lifespan of the three devices. It the three devices are handled carefully, they can last for a very long time.
It is noted that differences and similarities between the devices may be observed at the same time. To this end, two devices may share a common feature or functionality, which is not present in the third device. In other cases, all three devices may be totally different from each other. For example, binoculars use eyepiece lenses to view the image (Wan et al., 2012). The design of the binoculars involves two parallel telescopes. Each of the telescopic ends has an eyepiece lens. On the other hand, the Keratometer is computerized and the images are displayed on a monitor.
The computerized system is vital as it enhances the device’s measurement and calculation capabilities. The mode of image display used in the conventional Autorefracto is almost similar to that of the Keratometer. The device uses a liquid crystal display screen for imaging. Screens used in the device are colored to improve viewing and analysis of the image. The quality of the images generated is paramount to the success of the analysis carried out. The images display vivid details of the object analyzed.
Binoculars have two identical telescopes. As a result, the viewer is required to use both eyes in viewing the images. Each telescope in binoculars forms its own independent image. Though the telescopes function independently, one image is produced at a time (Wan et al., 2012). To avoid the generation of two images, the two telescopes are aligned parallel to each other.
Generation of two images may negatively affect the experience of the viewer using the binoculars. Binoculars have two lenses through which the user can view the image formed. On the other hand, the Keratometer displays the images on a monitor. To this end, the monitor provides a single interface for image viewing. The conventional Autorefracto is similar to the Keratometer. A single liquid crystal display screen is used to view the image. Just like the Keratometer, conventional Autorefracto provides a single interface, which is used in viewing the images generated.
Binoculars are capable of analyzing two focal spots at the same time. The capability is achieved by aligning the two telescopes independently. The independent alignment allows for independent focus for each of the two telescopes. Varying the distance between the object and the ocular lenses in the two telescopes generates two different focuses.
The Keratometer shares some of these capabilities. The device can analyze multiple focal spots. The device uses an array of microlenses in imaging. Each of the microlenses is used to analyze a given focal spot (Gutmark & Guyton, 2010). It is important to note that the Keratometer is used to analyze a single object. However, the various microlenses used help in viewing the object at many focal lengths.
The capability is of great importance in medical imaging, especially in analyzing the curvature of the cornea. Ophthalmologists can track the progress made during and after eye surgery. The conventional Autorefracto is capable of analyzing a single focal spot at a time. The device is only capable of analyzing a single beam of light passing through it. As a result of using a single beam of light, the device can only achieve a single focus at a time.
Binoculars lack the capability to technically measure the diameter of the field under view. In addition, the device lacks the capability to freeze the images generated. As a result, image viewing and image analysis are carried out simultaneously. The inability to freeze the images means that such images cannot be printed out for future reference. However, the binoculars can be mounted on a stand to enhance the stability of the image when viewing. Data concerning the image is collected when the binoculars are focused on the object. As a result of this, the accuracy in data collection is compromised.
On the other hand, the Keratometer is technologically advanced and its functionality incorporates image freezing capabilities (Gutmark & Guyton, 2010). Freezing the images allows for detailed viewing of the object. In addition, the images can be printed out for future reference. The ability to print out Keratometer images is important in providing high-quality healthcare services.
The new images are compared with older images of the same object to determine the progress made in treating the condition. Likewise, the conventional Autorefracto device has the image freezing capabilities. As a result, autorefracto images can be printed out. The ability to freeze the images allows the viewer using the conventional Autorefracto device to carefully analyze the image. What this means is that imaging and analysis of the same are not negatively affected by changes in the environment.
Binoculars are used to analyze various objects during viewing. However, only a single image can be viewed at a time. In addition, the size of the objects is fixed, but it is possible to modify the image to attain the preferred quality. Such aspects as the magnification of the image are altered to improve viewing. The alteration is achieved by adjusting the various components of the device.
The viewer has control over the quality of the image generated by the device. Similarly, the Keratometer is used in viewing fixed objects. The various components of the device are adjusted and modified to achieve the desired image. As a result of this, it appears that the image is the only variable in the viewing process (Gutmark & Guyton, 2010). Likewise, conventional Autorefracto is used in viewing a fixed image. However, the various components of the device are modified to generate an image that meets the needs of the viewer.
Binoculars use stabilization technology. The technology aims at reducing the shaking effect associated with visual diagnostic devices (Wan et al., 2012). Research has shown that high magnification is responsible for the shaking effect. Mounting the binoculars on a stand is one of the strategies devised to improve the stability of the images generated.
The Keratometer is stable, which means that its imaging is not negatively affected by the shaking effect. The stability is associated with the high quality of the images generated by the device. Likewise, conventional Autorefracto applies stabilization technology. The technology ensures that the images generated are clear. The clarity helps the viewer to analyze the details captured in the liquid crystal display screen.
Binoculars have refraction errors. The error is evident when the viewer acquires an image at different focuses. The images produced at this point are blurred. However, professionals and specialists can effectively correct refraction errors. The refraction errors in this visual diagnosis device are corrected by adjusting the realignment of the glass prisms used in the device. On its part, Keratometer is capable of measuring the refraction errors. The feature helps in detecting visual abnormalities in a patient.
It can detect such visual abnormalities as scratched corneas and cracks on the eye lens (Gutmark & Guyton, 2010). The ability to detect refraction errors makes Keratometer the preferred device in the diagnosis of vision-related problems. On its part, the conventional Autorefracto device is incapable of measuring refraction errors. Lack of this capability negatively affects the accuracy of the device. As a result, the device is less accurate compared to the binoculars and Keratometer devices.
Binoculars use mechanical components in viewing the object and generating the image. The pair of telescopes, which makes up the binoculars, is composed of an elaborate arrangement of mechanical components. The components include prisms, the ocular, and the objective lenses. The image is adjusted using movable joints between the two telescopes. In addition, the eyepiece lens is used in changing the focus of the telescopes.
Considering the fact that binoculars are mechanical devices, it is easy to differentiate them from the Keratometer and the conventional Autorefracto devices. The two devices (Keratometer and conventional autorefracto) are composed of a combination of mechanical and electrical parts (Wolffsohn et al., 2002). The mechanical components of a Keratometer involve an elaborate array of multiple microlenses. The electrical components of a Keratometer include the computerized monitor used in imaging.
In addition, the device is computerized to enhance the computation of refraction errors and other shortcomings in imaging. Moreover, computerization helps in performing the calculations needed in analyzing the image. Like the Keratometer, the conventional Autorefracto device is made up of a combination of both mechanical and electrical parts. The mechanical parts of the device include, among others, the lenses. In addition, the device has various electrical components. The electrical components set this device apart from the binoculars, which is more mechanical. Some of the electrical components in the conventional Autorefracto include, among others, the liquid crystal display screen and the various components used in adjusting and focusing the image.
Conclusion
Visual diagnostic devices operate on the principles of light refraction. The devices are used to analyze objects of interest to the practitioner (Koeppl et al., 2005). Each of the three devices has its advantages and limitations. The differences between the devices help the viewer in making the right decision regarding the device to purchase or use for a particular task or analysis. There are various structural differences between the devices. For example, two different models of binoculars may have different structural features. The different models are developed to suit the different needs of the consumers.
Advanced technology is used in manufacturing the devices to improve imaging. An example is the stabilization technology used to improve the quality of the image generated (Wan et al., 2012). The technique is used to reduce the shaking effect associated with an increased magnification of the image. Stabilization is achieved by, among others, mounting the device on a firm base. However, the technique interferes with the clarity of the images generated.
The use of glass prisms in the three devices highlights the importance of prisms in imaging. The prisms perform better than mirrors given that very little light is lost through refraction (Glasser, 2008). In addition, the prisms do not absorb light, especially if they are polished. Failure of prisms to absorb light energy improves the clarity of the images.
Selecting the visual diagnostic device to use solely depends on the preference of the user. Viewers tend to go for the devices that best suit the task they intend to carry out. The three devices are used in the diagnosis of vision disorders. As a result, the quality of the images generated is crucial in determining the effectiveness of treatment procedures initiated to treat the disorder.
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