Central and Peripheral Vision & their Diseases

The act or power of seeing
The special sense by which the qualities of an object (such as color, luminosity, shape, and size) constituting its appearance are perceived through a process in which light rays entering the eye are transformed by the retina into electrical signals that are transmitted to the brain via the optic nerve.
Types of Vision
Central Vision
Peripheral Vision
Disease of Vision
Central Vision Loss
Peripheral Vision Loss

1. Central & Peripheral Vision Memoona Arshad Group 11 – Semester 7 th ISM – IUK Presented to : Kenjebek kyzy  E

2. Vision The act or power of seeing The special sense by which the qualities of an object (such as color, luminosity, shape, and size) constituting its appearance are perceived through a process in which light rays entering the eye are transformed by the retina into electrical signals that are transmitted to the brain via the optic nerve. Types of Vision Central Vision Peripheral Vision Disease of Vision Central Vision Loss Peripheral Vision Loss

3. Central Vision VS Peripheral Vision Eye sight can be seen (pun very much intended) as being comprised of two main functions: Central Peripheral. Most associate central vision with focusing on particular objects of interest, while peripheral vision is when something to the side attracts attention. Both act as a function of the human retina, which is made up of two types of photoreceptors: rods and cones. Rods are responsible for vision at low light levels, while cones are active at higher light levels. However, both central and peripheral do much more and provide use that many may not be aware of.

4. Central Vision Central vision is probably the one that is more straightforward. Perhaps regarded as the more important of the two, central vision is responsible for most of the active functions that someone uses. Reading, driving, recognizing colors and shapes, and general focus-based detail-oriented sight tasks are fulfilled by the use of central vision. This all comes from the very centre of the retina at the back of the eye, also known as the macular and is where there is a high concentration of cones. If this area is damaged, it can cause vision to become blurry and dull. Eventually it may lead to dark patches appearing.

5. Etiology of Central Vision Loss You can have central vision loss if you have a condition that affects the macular area or tiny fovea. It can begin with a small dark spot in the center of your vision that expands with time or it can be distortion to your vision, making straight lines look wavy and details (such as faces or pictures) seem twisted or otherwise abnormal. Keep in mind that this can happen pretty quickly. So, if you notice any changes to this vision, you should immediately consult with your eye practitioner. Central vision loss can commonly occur with conditions such as the following: Diabetic retinopathy Age-related macular degeneration (AMD) Macular hole Central serous chorioretinopathy Choroidal neovascular membranes Coloboma of the retina Diabetic macular edema Histoplasmosis Hypertensive retinopathy

6. Symptoms of Central Vision Loss The loss of central vision can affect visual acuity, which is the ability to discern shapes and details in one’s vision. Those who lose central vision often feel like they are missing fine details or seeing blurred spots in the center of their visual field. As the underlying disease and the damage it causes progress, the blurred spots will eventually turn into dark or “blank” spots. Losing central vision is the result of damage to specific tissues and structures within the eye, which can originate from multiple causes, including: Macular Degeneration Glaucoma Cataracts

7. Diagnosis of Central Vision Loss Diagnosis of central vision loss is made after testing by an eye doctor to determine abnormalities in the central visual field. A common test used is the Amsler Grid, where graph paper with a dot in the centre is presented to the patient. The lines around the dot w ill appear straight to people with healthy eyes, whereas the lines will appear distorted and/or wavy to people experiencing central vision loss.

8. Peripheral Vision The general public are often aware of the importance of peripheral vision. It is not something that people actively use, but this doesn’t mean that it is less important than central vision. Peripheral vision helps to process spatial information received through the eyes and is an important cog in our innate fight or flight response system. Any activity that involves space (and many ones that don’t) can be improved with better peripheral vision. This is due to spatial information combining with body mechanics to produce correct and precise movements. For example, if someone is dribbling a football towards a goal, their peripheral vision can inform them of an impending opponent coming from the side. Good peripheral vision gives the player the opportunity to avoid the challenge posed. Bad peripheral vision may leave the player dining on dirt .

9. Etiology of Peripheral Vision Loss When someone experiences a loss of their peripheral vision, it is sometimes referred to as "tunnel vision.“ To get a better idea of what is going on in an eye with peripheral vision loss, we must look to the two types of cells in the retina that respond to light: Cones Most of the cones are located in the center of the retina (also known as the macula) and allow us to see details and colors. Rods These are in charge of our peripheral and night vision, and are located throughout the rest of the retina. So when someone has an eye condition that impacts the rods' function, that could lead to the loss of their peripheral vision—even if their cones are still fully operational.

10. Symptoms of Peripheral Vision Loss Loss of peripheral vision can happen gradually—to the point where a person doesn't notice the onset—or suddenly, in which case it can be alarming and scary. Though in some cases (especially when the vision loss is gradual), people may not notice any signs that they're living with a limited view. But in other cases, there are a variety of signs that are hard to miss, including: Tripping Having trouble walking in the dark Difficulty driving Reading much slower than usual Shimmers of light followed by tunnel vision lasting 10 to 20 minutes

11. Diagnosis of Peripheral Vision Loss Your doctor will diagnose the cause of your blurred vision by first taking an inventory of your symptoms. Examples of questions they may ask include: When did you first start noticing the blurred vision? What makes the blurred vision worse or better? They may also ask about your personal medical history as well as a family history of eye conditions . Eye tests Blood tests

12. Treatment of Peripheral Vision Loss Temporary peripheral vision loss like from migraines will go away on its own, but other peripheral vision damage may need special care. In some cases, there are treatment options to restore your peripheral vision, but other times the damage cannot be reversed. Depending on the cause of the peripheral vision loss, your doctor may prescribe a variety of treatment or management strategies such as eye drops, surgery, or lifestyle changes. To prevent peripheral vision loss or slow the progression, there are a variety of things you may be able to do including: Getting regular comprehensive exams of your eyes Letting your doctor know of anything eye diseases that run in your family Maintain a healthy diet Exercising regularly Following your doctor’s recommendations if you are diagnosed with a problem.

13. References Peripheral Vision Loss: Causes, Diagnosis, & Treatment Options - Ideal EyeCare (idealeyecare2020.com ) Blurred Vision: Causes, Diagnosis, and Treatment (healthline.com ) Vision Definition & Meaning - Merriam-Webster Central Vision vs Peripheral Vision - OXSIGHT (oxsightglobal.com)

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