Category: Vision

Phenomenal vision is the sight of “colors, brightness, depth, shades, and motion”, generated by light distributed on the retina (Stoerig, 2001). Undeniably, there are phenomenally unconscious visual mechanisms occurring within an individual’s retinal processes and occipital lobe activity does not correlate with visual awareness. Research into the study of vision and whether the phenomenal vision is mandatory to be aware of visual stimuli has extensively been researched in blindsight patients (Brogaard, 2011). Specifically, striate damage results in profound homonymous loss, resulting in cortical blindness. Extrastriate damage affects specific losses, color vision, and motion abnormalities. Subcortical damage involves processing impediments before signals reach the cortex (Wurtz and Albano, 1980). Notably, type 1 blindsight, reveals individuals are unaware of any stimuli but can predict aspects like location or movement of a stimulus. Type 2 blindsight holds some awareness but no visual perception (Fuchs, 1921). Blindsight occurs when damage is present to the primary V1; potentially resulting in blindness across the full visual field however, some are still capable of predicting the location and motion of visual stimuli. The primary visual pathway derives from the retina and projects to the occipital lobe via the lateral geniculate nucleus. Visual information reaches the extrastriate cortex along the ventral and the dorsal stream. (Braddick and Atkinson, 2011). Subcortical sites are associated and transmit direct projections to the extrastriate visual cortex. Damage to structures in the dorsal and ventral stream can impair visual perception while leaving some mechanisms intact (Diederich et al, 2014).

Gelder et al, 2008, demonstrated phenomenal vision is needless regarding the awareness of a visual stimulus. Brain imaging of a patient with bilateral damage to the primary V1 has suffered complete clinical blindness, a lack of functioning in the visual cortex, and a loss of posterior fibers however could successfully complete a ‘residual visual abilities test’. This demonstrates extra-striate pathways can sustain visuospatial, locomotion, and navigation skills in the absence of perceptual awareness. Conversely, Stoerig, 2001 states: absolute blindness is the absence of all visual qualia due to damage of visual structures and cortical areas that need to be activated in both veridical and non-veridical phenomenal vision. A unilateral lesion affects the visual field in one eye and both eyes if it is behind the chiasma (Mazzi et al, 2019). Patients who have experienced the destruction of visual regions are blind, do not see stimuli present in the blind field neither ‘after-images’. Magnetic brain imaging simulation provides support, demonstrating the association between primary V1 inactivity and visual blindness (Burton, 2003)

Arguably, Overgaard et al, 2008 improved methods for detecting awareness in blindsight patients report that visibility of stimulus correlates with accuracy in both healthy and blindsight individuals indicating blindsight is essentially a ‘highly degraded conscious vision’ confirming awareness of visual stimuli are still intact. She and Von Cramon, 1979 provided further clinical support. Those suffering from postchiasmatic visual field defects were trained using light-difference thresholds. Improvements in contrast sensitivity, visual acuity, color perception as well as visual field enlargement were obtained. Likewise, Balliet et al, 1985, undertook 89,000 visual field training trials for patients with homonymous, hemianopia or quadrantanopia caused by occipital lesions. Tests for light sensitivity demonstrated patients, did not have significant visual field differences when compared to controls as they reported no change in vision suggesting lesions do not necessarily result in a complete loss of function to the visual system.

Nevertheless, Sahraie et al, 2003 undertook research on trans-neuronal retrograde degeneration. Evidence portrayed that a lesion cause’s lack of neuronal communication, therefore, cells anterior to the lesion degrade, and damage extending to the thalamus disrupts transmission from LGN through fibers, therefore, no residual visual ability is present. This indicates these elements are essential in visual awareness and damage to brain structure involved in visual processing can cause permanent visual impairment.

Contrariwise, Weiskrantz, 1986 ‘commentary key paradigms’ provides support for awareness without phenomenal vision. Blindsight patients have revealed, discrimination is possible for certain visual events. They are not aware, however, to achieve this through a temporal guessing task. When patient’s photosensitive retinas were stimulated, they could identify, localize, and distinguish targets when forced to guess whether, where, or which stimulus had been presented to their blind field. Kentridge, 1999 case study shows, patients reported awareness of salient stimuli presented to their blind field depending on stimulus contrast. Vague sensations of visual awareness were reported at ‘75% contrast’ indicating phenomenal vision is meaningless regarding visual awareness. Huxlin et al, 2009 used moving, ‘complex global dots’ and ‘simple local gratings’ to test visual awareness in blindsight subjects. Additionally, initial blindsight monkey studies revealed pupil dilation in response to a motion supporting this concept (Humphrey, 1974). Although V1 damage impaired visual awareness, repetitive training improved direction discrimination. Nonetheless, Sahraie et al, 2010 conducted regular blind field stimulations for hemianopia patients including several sessions and thousands of trials. Findings indicated that both accuracy and awareness improved, again, providing support.

The study of phenomenal vision in the visually impaired has been a controversial subject. While numerous studies argue to have provided conclusive evidence for the presence of blind field qualia, others often reveal difficulties in interpreting results. From previously discussed literature, it is evident there is more empirical support regarding the idea: we do not need phenomenal vision in order to be visually aware. Many studies reveal, those who are visually impaired or experience blindsight still express awareness to visual stimuli, yet in the absence of phenomenal vision. Empirical evidence overrides the opposing argument, however, a limitation, is the use of case studies conducted on single patients. Findings cannot be generalized neither applied reliably unless replications have produced similar valid results. Conversely, some have undertaken numerous trials that overcome this. Future studies should be directed into examining, brain regions and actively involved in those with impaired vision. Furthermore, how the brain adapts via plasticity to compensate for V1 lesions. Furthermore, studying why there are incidents of phenomenal awareness even in the absence of the primary visual brain regions; especially as the visual cortex persists to unconsciously process visual information, would be an interesting future focus.

Introduction

Human bodies are capable of doing amazing things every single day, which we often neglect. One of the most underestimated organs is the eyes. They are our window to the world yet a large number of people are not interested in how they work. This can lead to a misunderstanding and lack of knowledge about how to take proper care for them. In turn, this can have fatal consequences. If you finally have understood their importance and you want to learn more about them than this is the article for you!

How the eyes work (the basics)

The light enters the eye through the cornea – the transparent layer in front of the eye. She can bend the light rays so they pass through the hole (the pupil) of the iris. The iris is the colored part of the eye that surrounds the pupil. It can be black, brown, blue or green, depending on the amount of melanin that the eye contains. It opens and closes which changes the size of the pupil. This way, the iris regulates the amount of light that goes through. Then the light rays pass through the lens, which can change its form. This way it’s able to bend the rays and focus them on the retina. The retina sits at the back of the eye. She is a thin layer of tissue that contains around 130 millions of small nerve cells able to sense the light. The nerve cells are called rods and cones due to their form and structure. They convert the light into electrical impulses. These impulses are being sent to the brain by the optic nerve, which produces an image. In bright light, cones provide clear central vision and reveal colors and tiny details. Thanks to the rods we have a side vision and we can see during the night.

How to take proper care of the eyes

Now that you are aware of the way your eyes work, it is time to look after them. There are plenty of things you can do daily to make sure your eyes are healthy.

Try to follow these 6 simple rules for optimal results:

Keep a balanced diet

Eating healthy and nutritious food can have a serious effect on your eyes. Try to incorporate more foods rich in vitamins A, B6, B9, B12, E, C,omega-3 fatty acids, lutein, thiamine, riboflavin, etc. For example, sweet potatoes, leafy and collard greens, nuts, tropical and citrus fruits, fish, beef, milk, yogurt, etc. Don’t forget to stay hydrated and drink plenty of water!

Use sun protection

Sun may be your main source of Vitamin D but it can be also dangerous especially when it comes to your eyes. Therefore, you should consider buying sunglasses. This way you will be not only fashionable but also healthy. If for some reason you are not a sunglasses fan, you can try eyeglasses or contact lenses with UV protection.

Observe the 20-20-20 rule

This rule is very simple yet very important for keeping your eyes in good condition. Every 20 minutes shift your gaze from the screen and look at something 20 feet away for 20 seconds. This way your eyes will rest and recover from the constant staring at the monitor.

Maintain good hygiene

Your hands are way dirtier thank you probably think due to constant physical contact with both people and objects. For this reason, it is very important to avoid touching your eyes. Neglecting this tip can lead to infection and irritation. If you wear makeup that is another thing you should take into consideration. There are a few things you should do daily. First, make sure that the products you use won’t lead to an allergic reaction. Second, always remove it before going to bed. Any leftover makeup in the eye area can lead to infections. Third, wash your brushes regularly.

Visit your ophthalmologist

Going to an eye doctor at least once in a year is crucial for your eyes’ health. It is important to take preventative measures. Don’t wait until a serious medical condition appears. If you go to your ophthalmologist often the chance to heal it’s much bigger.

Protect your eyes from blue light

Screens emit blue light that can be very dangerous for the eyes. It can lead to digital eye strain and macular degeneration. Don’t worry! Iris software got you covered. Iris software is a program for eye protection, health, and productivity. It decreases the amount of blue light and controls the brightness. How you may ask? Iris automatically detects if it’s day or night. Based on that, the program changes the color temperature and brightness. You have the freedom to choose between different modes and types. This gives you the option to customize it as much as you want. You can try the different versions of Iris and see which one suits you best. For example, there is Iris Mini, Iris Macro, Iris OS, etc.

Our eyes work like a camera. However, unlike the camera, they work constantly without a shutdown option. They show us the world the way he is – with all of his glory. Knowing how your camera works, makes taking care of it easier. The same thing applies to your eyes. For this reason, in this article, we talked so deeply about how they function. Now that you are educated enough on this topic, you are capable of treating them the right way.

Try to stick to the tips above. They are crucial for your eyes’ health and your overall well-being too. You will see an improvement when you start applying them every day. They are all very important – from eating properly to downloading a blue light-blocking software like Iris. Take care of yourself – your body is the only thing you will have forever.

Introduction –

Vision is maybe the key of our means. Certainly, all sections of the eye are critical for viewing a conventional picture, the most fundamental layer for illusion is the retina. The retina is a bit of neural tissue that lines within the eyeball. The vivid intensity that drops on the neural cells of the retina is changed over into a lot of electrical notion that is transferred to the visual focuses of the mind.

All around the world, more than around 1.5 million individuals have dynamic vision privation. In Australia, more than 50 thousand individuals experience significant visual impairment. The estimated expenditure expense of significant vision privation is remarkable. In Australia itself, has been evaluated at $2.5 billion yearly.

In a bionic eye, we sidestep the visual presentation and that sends the electrical signs from every pixel in the camera to the variety of animating cathodes situated on the eye. At the point when it is set into the eye of a visually impaired patient, the cathodes incite the nerve cells that would typically get the contribution from the missing photoreceptors. The nerve cells have no mark that the electrical incitement they are encountering is through an anode batch. The Nerve cells interpret the signs as those anodes originating from typical photoreceptors. The camera converts images into electrical movements that begin remaining retinal cells. Hence, the cells are then sent as visual information onward the optic nerve to the brain, where is illuminated as an image. Thus in this way, the bionic eye imitates the function of the retina and reestablishes a sense of clear vision. The Bionic Eye was developed in Australia by Bionic Vision Australia in 2009.

Designers and Designers practice/processes

The NVRI have an extraordinary group that has the experience and information required as building up the Bionic Eye. With three refined retinal auditing systems, the NVRI is a world-driving focus in retinal physiology, especially in the field of electrical incitement. The bionic work is firmly upheld by Bionic Vision Australia (BVA), an association set up in 2009 to build up an Australian-planned bionic eye and financed by a unique program from the research council in Australia. Bionic Vision Australia (BVA) is a national association of analysts from The Univesity of Melbourne which are the regulating association, Eye Research Australia, National ICT Australia the Univesity of New South Ridges, Western Sydney Univesity, National Vision Research InstituteBionics Institute, and Royal Victorian Eye and Ear Hospital who are attempting to design bionic eye implement that will reestablish the scene of vision to individuals who suffers vision disability.

The processes behind developing bionic eyes in order are technically formidable. Critically, it accepts a generous limit of learning about the retina and certainly about how prosthetics cooperate with the retina. In particular, the exploration expects them to see how the retina reacts to the infused electrical charge. Of course, over the most recent couple of decades researchers in the field of vision have been centered around seeing how photoreceptors and visual nerve cells react to light. As such, most research has been centered around understanding typical visual capacity. Just as of late, with the possibility of creating bionic eyes, have the electrical properties of the retina turn into a subject important to researchers.

Research and improvement of vision processing techniques are for the genuine bionic eye immersed are being finished at the NICTA (Computer Vision Research Group in Canberra). Further, every single patient’s involvement with a bionic eye will be extraordinary and thus the vision they experience may not be the same.

Creativity –

There is nothing happier than seeing the world with our very own eyes. Sadly, a few people around the world aren’t able to visualize it. As indicated by a WHO report, an expected 253 million individuals live with vision hindrances around the world. Among these 36 million are totally visually impaired and 217 million people have moderate to serious vision trouble. In spite of the fact that organ gift is a conceivable answer for the issue, religious convictions, uneducated attitudes and a few different issues make it amazingly hard to discover supporters. So we required another achievable method like Bionic Eye which has resembled an encouraging future to handle the current problem. The standard idea of a Bionic Eye is a mechanical eye associated with the brain. In any case, the Bionic eye innovation doesn’t fit with such an idea. The present creative arrangement is a framework containing a couple of glasses, which is embedded in the retina.

The innovative system is known as PRIMA (Photovoltaic Retinal IMplAnt). PRIMA comprises of retinal implants, a couple of glasses with a video recorder and an internally built PC. The camera inserted in the glasses takes an image of the environment around the person and afterward it exchanges it to a pocket PC for assembling. The formulated pictures are then sent to the glasses to shaft them to the retinal implant as beats of close infrared light. The gadget has been effectively tested previously in 2013.

Factors Affecting design –

Bionic Vision Australia (BVA) is an association has globally driven Australian researchers, who are cooperating to develop a progressive Bionic eye. The agencies that have been involved in the innovation are the people from the Bionic Institute, University of NSW, the University of Melbourne, The CERA and The NICTA in Canberra. The mastermind site for the principle of installing the retinal is associated with the Ear Restorative Centre and The Victorian eye.

Entrepreneurial activity –

Australia has had a wealthy past in the region of medical Bionic projects, let it be the cochlear plant up to pacemakers, also clearly well-known around the world as ‘Bionic ears’. Bionic Vision Australia is really lucky from their successful past encounters and the perception of developing a globally well-known medical product into the marketplace that could help millions of people around us. Bionic vision Australia have been taken the idea of the Bionic eye in the marketplace as one of the most inherent products which would cure individuals who have visual impairments.

The Impact of emerging technology –

The product Bionic vision has turned out to be a succinct feature of fiction and it is more about the quest of logical research. Progressions inside the domain consist of much-emerging technology required in developing this product such as fast computers handling high power, wireless internet, neuroprosthetic devices, science materials, remote innovation and use of microchips, which have intended to help blind people to see the real world. Advancement in Bionic Vision Australia is certainly becoming at high speed it is possible because of the latest and wireless technology like PC which is able to process algorithms that have a scope of the safe product.

The impact on Australian society –

A major downside is a device requires a more invasive surgery than the Argus II. A small section of the skull needs to be removed to expose the area of the brain where the array of electrodes is placed. Because electrical brain implants carry risks like infection or seizures, the first clinical trial will be small, and the company will start off by testing the implant in patients who are completely blind.

There also exists the issue of how a captured image is co-registered with the natural movement of the eye. Inappropriate compensatory eye movements may lead to perceptual mismatch, causing the patient wearing the implant to mislocalize objects in the external world.

The National Eye Institute, says a brain implant will be more difficult to get right than a retinal implant because the brain’s visual cortex is so much more complicated than the eye.

Historical/ Cultural influences –

Monash vision group contains a group of 40 to 50 scientists, they believe the Bionic vision is on track to become the first around the world to embed the microchip into the brain of a patient with vision impairments. The patient will have to set on Bionic vision glasses which contain a small camera that certainly works like the retina in the eye. The pocket PC diverts those pictures were taken with the camera into electrical signs which then get sent through the microchip in the brain.

We additionally have researchers required from two supporting associations: the Australian National University and the University of Western Sydney. There are a little more than 100 researchers and understudies taking a shot at different pieces of the venture.

Ethical and environmental influences –

The greatest portion of these individuals live in developing countries and the majority of the leading causes of blindness are actually avoidable and/or treatable. Thus, the restoration of functional vision through a visual prosthesis will likely target only a restricted segment of the blind population. Moreover, it is important to realize that not all individuals and all forms of visual impairment could potentially benefit from a visual neuroprosthesis. As presently conceived, visual prosthetic devices have been designed for individuals with profound vision loss and who have had normal visual development as opposed to congenital causes of blindness. Furthermore, as these devices are designed to interface with viable neuronal tissue, the site of damage and nature of pathology will largely dictate whether a prosthetic device can be feasibly implemented. For example, in conditions where the overall functional and structural integrity of the retina is compromised, a retinal-based visual prosthesis is unlikely to be effective in restoring visual function

The ethical future of bionic vision is somewhat cloudy, but Professor Ibbotson and others at the Bionics Institute who have been strong proponents for the advancement of bionic vision in Australia maintain there is an ethically justifiable balance of benefit and risk.

Conclusion –

These improvements in vision can really boost a person’s sense of independence and confidence. The bionic eye aims to restore basic visual cues to people suffering from eye diseases, which is a genetic eye conditions. The loss of sight can have a devastatingly negative impact on the quality of life of an individual. Such insight could help to develop and refine strategies for merging visual sensations that are generated by the prosthesis.

In this essay, I have chosen to review the article “The dimensionality of color vision in carriers of anomalous trichromacy (Jordan et.al, 2010)”. The purpose of this essay is to show the differences and similarities between primary and secondary articles as well as how secondary articles are gathered and findings taken from primary articles. This article explains how some women may be carriers of the rare condition called Tetrachromacy where individuals have four working cones in the retina, rather than three. As a result of this condition, this abnormal condition allows individuals to see colors that normal-visioned humans wouldn’t be able to. The article is derived from the Journal of Vision, which is aimed for scientists and researchers in the area of vision science and biology, as well as some parts of neuroscience. Specifically, in this article, the disciplines include vision science and biology, related to genetics. Although this article does not specifically state which audience it is aimed at, it is clear by the use of scientific language and statistics that it is aimed at those with a scientific background and those who are interested in rare scientific findings. My understanding of visionary science is that it is study of vision and its functions. As well as this, biology is an interdisciplinary science that can correlate highly with vision science explaining the functions and processes of vision in biological organisms. I believe that the combination of the science disciplines allows scientists and the public to discover unique and rare genetic conditions that could be advantageous in the future.

Journal of Vision

The review article I chose was found on PubMed’s online search engine of life science articles and journals. The peer-reviewed ‘Journal of Vision’ encompasses the science discipline of life science because vision is important for all living organisms to see. Commonly, given by the name of the journal, vision science has a strong relationship with this journal as its main focus of articles are related to visual functions and conditions. I also believe that the journal correlates with functional biology as it contains articles that explain the processes of vision and its relationship with the central nervous system. The Association for Research in Vision and Ophthalmology (ARVO) is an organization that researches vision and eyes and is well-known worldwide (Arvo Journals, 2015). This organization is responsible for publishing three peer-reviewed articles including the Journal of Vision. Overall from my understanding the Journal of Vision, it is not associated with one discipline of science, but a variety of sciences that all correlate with each other.

A primary article is used to link information with other primary articles to create a secondary article. I chose the primary article “Colour Discrimination in carriers of color deficiency (Hood et.al, 2006)”. The article explains how individuals who carry color vision issues experience some problems with color matching and discrimination. Colour discrimination is the ability of the eye to recognize colors from each other (Konica Minolta, 2011).

Aim

The aim, which was found in the abstract, was to take 55 samples of carriers of protanopia (individuals with red-green color blindness and are missing red cones) and deuteranopia (individuals with red-green color blindness and are missing green cones), and another 55 age-matched controls to determine color discrimination. The primary article contributed to the rising research area in biology and vision science of tetrachromacy and how it can be genetically passed on.

Hypothesis

It was hypothesized that carriers of color vision problems displayed issues of color discrimination. They also suggested that those with deuteranopia have fewer issues than the controls, while those with protanopia who have color discrimination have a closer relationship with the control group.

The hypothesis was found in the results and discussion however from my experience, it was hard to locate and understand.

Results

Hood et.al (2006) discovered that those with deuteranopia experienced color discrimination while those with protanopia had normal color discrimination. This is because those with deuteranopia have middle wave-sensitive cones and those with protanopia have long wave-sensitive cones in the retina. They also described that the variance of middle and long wave cones is the cause of colour discrimination and that two cone types are more abundant in individuals with deuteranopia.

Contribution

The primary article is sufficiently mentioned in the general discussion part of the article, relating to explaining that there is impaired colour discrimination when there is a different amount of cone cells in individuals’ eyes. A figure from the primary article was also used in the Jordan et al. (2010) article, however, it is not available to look at properly within the article.

I chose this article as I found the genetics discipline and vision science discipline interesting, however, I believe that the primary article may be better understood by experienced and advanced visionary scientists and biologists. Although I did have to research the two different types of red-green color blindness, it was still confusing to make sense of the methods, results and discussion as I have no previous experience with the discipline of vision science, only a basic high school level of biology. It may be suitable for students in BABS1201 studying vision science, however, I believe that it the results and discussion were detailed with scientific terms that I couldn’t understand.

Review article vs primary article

Review articles are a summary of a research area using a range of primary articles. To compare, the primary article had a somewhat significant contribution to the review article within the general discussion, as shown by the date referencing used within the Jordon et al. (2010) review article. From the primary article (Hood et al., 2006), parts of the results were included in the review article. The primary article was more difficult to understand and read as it had a formal and complex scientific form. On the other hand, the review article was easier to read and understand although there were some difficult concepts to interpret. The primary article clearly followed the structure of a scientific article thus it was easy to find the different parts of the article. Similarly, the review article also adhered to a non-specific structure but was divided into sections that were easy to understand.