How does the retina work?

Retina is the screen on the inner layer of eye on which the images are formed by the lens and what is projected on them. The eye is very similar in structure and function to a modern digital camera. Retina, a thin membrane in the eye, is full of nerve supply resting on a highly vascular layer. It corresponds to the sensor of the camera.

The nerves convert the light falling on it into electric signals through a series of chemical-electrical reactions and is transmitted via the optic nerve to the brain for interpretation. In front of the eye is a self-adjusting lens over which is a diaphragm called iris which regulates the light entering the eye, while the lens automatically adjusts its focal length to some extent. The focusing is done by the muscular wall of the eyeball. There is a transparent cover to the lens called the cornea.It is clear that the most important part of the eye is the retina.

The retina covers about 65% of the inner area of the eyeball. It consists of 3 layers of neural cells: starting from the inside are the ganglion cells, a middle layer of bipolar cells and an outer layer of photosensitive cone and rod cells and the retinal pigment epithelium layer. These 3 layers are attached to the inner wall of the eyeball called the choroid inside the outer layer sclera, the visible white portion.

Roughly about a 125 million of photosensitive cells (0.002mm in diameter) are inter-mingled non-uniformly over the retina. The rods are the more sensitive to light than the cones, but are incapable of discerning color and the images they form are not well defined. On the other hand, 6 to7 million cones (0.006mm diameter) can be taken as a separate overlapping layer of slow acting color film. It gives color discerned, well-defined images in bright light.

In the middle of the retina is a depression called the macula or the macula lutea or the yellow spot’. In the middle of the macula is the fovea centralis or fovea. This gives the sharpest images of the highest color perception possible and is the center of direct vision. As it has only cones, it is less light sensitive.This small area has about 30,000 cones connected to individual neurons. Very close to this spot is the blind spot from where the optic nerve departs. The rods, unlike the cones, are connected to nerves and a single nerve fiber can be activated by any one of the hundred rods.


  • Things to keep in mind before buying MacBook Pro
    Are you planning to invest in a good Apple computer? With so many options available, the best way to go about with it is to understand your requirements. Apple computer series called iMac is one of the best in the market today. The new Apple computer comes with high technology retina display and latest graphics technology, which give you a superior overall desktop experience. Another popular Apple product you can buy is the MacBook Pro. Here are some things that you should know about this Apple product:
    • The MacBook Pro is much heavier than the MacBook Air. In fact, the MacBook Pro is the heaviest of the Apple notebooks that you can buy. So, think about this factor before you decide to go for this option.
    • If you consider the price of MacBook Pro against the features that it entails, you will conclude that though MacBook Pro comes with ancient features, it comes for a price tag that will create a big hole in your pocket.
    • The new MacBook Pro does not come with an SD card slot and other ports. This means that if you buy MacBook Pro, you will have to invest in MacBook accessories like USB C adapters. Not just that, MacBook Pro also comes without the much-desired feature called the MagSafe connection. This means that if you are not careful and someone trips over the cable, then your MacBook Pro will fall off your desk.
    • If you are planning to buy MacBook Pro for professional purpose, then keep in mind that most of the professionals, these days, work on the latest DDR4 standard of RAM, while MacBook Pro comes with the older and slower DDR3 standard of RAM.
    When it comes to MacBook Pro, this Apple computer was created keeping in mind the professional requirements of photo editors and video experts. So, if you are buying an Apple product for general surfing and your Netflix and chill sessions, then instead of buying MacBook Pro you must invest in any other cheaper Apple computer.
  • Important facts about night sweats
    Sleep hyperhidrosis commonly referred to as night sweats results in totally drenched sheets and sleepwear regardless of the fact that the sleeping environment is quite pleasant and refreshing. This issue is common with around three percent of the people and can be the indication of an underlying serious illness. The most common triggers of night sweats There are quite some causes for night sweats to occur the main reasons being
    • Different hormone imbalances: There occur various kinds of hormone imbalances triggered by various factors like diabetes, menopause, puberty, thyroid issues and pregnancy. All these are possible triggers of night sweats.
    • Infections: One of the most common infections that can trigger night sweats is tuberculosis. Other triggers include infections like influenza, HIV and other types of febrile illnesses.
    • Obesity: This condition also causes night sweats.
    • Gastro oesophagal Reflux Disease: Commonly known as GERD, night sweating is one of the most common indications apart from heart burns which are another symptom of this disorder.
    • Obstructive Sleep Apnea: This is a disorder that causes the constriction of your throat causing breathing issues. This condition can trigger night sweating in patients if left untreated.
    • Cancer: Night sweating can also be an early indication of cancer especially leukaemia or lymphoma.
    • The adverse effect of certain mediations: A lot of medications like diabetic medicines, antidepressants, hormone medicines and steroids can trigger night sweating. The common medicines that trigger this side effect include Bupropion, Albuterol, Glipizide, Ciprofloxacin, Trazadone, Esomeprazole, Atorvastatin and Amlodipine to mention a few of them.
    How to treat night sweating The treatment for this condition depends on the underlying cause that triggers the condition of the night sweating. It can be treated either by setting right the hormonal imbalances that have been triggering the issue or adjustment of certain medicines that have been responsible for this adverse effect. If not, finding out the cause of this condition and providing the required treatment accordingly is the next option. Suppose the doctor does not find out any direct cause for this condition, treating this includes managing and preventing these occurrences through various means that include
    • Averting use of extremely warm blankets
    • Sleeping in a very cool ambience
    • Restraining from using alcohol or spicy food before retiring to bed.
  • Attractive trade-ins and deals for the iPhone 12 Pro Max

    Apple fans all over the country are going gaga since the “Hi, Speed” launch event yesterday (October 13). Given the global circumstances, Apple was unable to hold a live event, followed by a hands-on. Yet, Tim Cook and the rest of the iPhone crew left the digital audiences awestruck with a pre-recorded, breathtaking launch of the latest iPhone 12 Pro Max 5G.

    What we saw

    The event featured the new iPhone 12 series, MagSafe technology, cases to go with the smartphones, a leather wallet, and the HomePod mini. The best part of the event? Apple offers deals at some of the most attractive prices, especially with the all-new Apple A14 Bionic chip and the 5G functionality across the iPhone 12 line-up. For those of you looking to purchase the best version of the iPhones, the iPhone Pro Max can be the “Apple” of your eye.

    About the iPhone 12 Pro Max

    The iPhone 12 Pro Max comes with a massive 6.7 inch Super Retina XDR OLED display with systemwide color management, offering a better color and viewing experience. The Pro series of the iPhone 12 also features the all-new LiDAR Scanner that’s capable of measuring light distance and using pixel depth information of a scene. The iPhone 12 mini features a more compact screen size of 5.4-inches, while the iPhone 12 and iPhone 12 Pro feature 6.1-inch panels. There’s a design for everyone!

    iPhone 12 Pro Max 5G deals

    The latest iPhone 12 Pro Max will be available in three variants: 128GB, 256GB, and 512GB at $1,099.00, $1,199.00, and $1,399.00, respectively. AT&T also offers attractive monthly payment deals as low as $13.30/mo. over 30 months after trade-in and AT&T bill credits. Verizon users can get the iPhone 12 Pro Max for $27.45/mo. over 24 months after trade-in and Verizon bill credits. Note that these deals aren’t up on their websites yet, but they will be soon.

    The rest of the “table-spread”

    The iPhone 12 Mini is available for a starting price of $30.37/mo., the iPhone 12 for 34.54/mo., and the iPhone 12 Pro for $41.62/mo. If you’re getting a new iPhone 12, check out the cool new accessories too. Pro-tip: The pacific blue is a gorgeous color you should look out for in the iPhone 12 Pro Max.

  • How to choose suitable aluminum wire nuts
    Wire nuts or connectors are often used to secure connections for switches, fixing lights, receptacles, and many other devices. If you are looking to buy these for a wiring project, you have come to the right place. Here is a simple guide on how to choose suitable aluminum wire nuts. Size and color matters Aluminum wire nuts come in different colors and sizes, and there is no one-size-fits-all. You can tell that a nut is wrong if it is too big or too small to accommodate the wires being connected to it. The packaging of the nuts often has a chart that tells you what color of nut you are supposed to use with which kind of wire. For example, a gray nut may accommodate two 22 gauge stranded wires. Consider the environment It is essential to understand where the electrical wiring is going to be placed. Sometimes, you may want to use the wires in a hot environment or in a hazardous location where there will be toxic gas or combustible liquids or vapors. In these circumstances, you will have to check if the wire nut has proper insulation, and in case of a hazardous environment, the connector should have a protective shield. Strip the wire ends properly Before you connect the wire to the connector, you need to strip the tail end. You can use a wire stripping tool for this purpose. While performing this step, keep the connector package handy. The label usually mentions how much of the bare wire you can expose. In most cases, it is approximately 1/2 or 5/8 inches. Exposing too much or too little of the wire can lead to a faulty connection. Choose the ideal aluminum wire nut Different projects demand different kinds of wire nuts. Twist-on wire connectors are typically used in wiring for ceiling fans, light switches, can lights, and so on. Conversely, winged twist-on connectors are used in large projects where establishing multiple connections is required. They make easy-to-use, fast, and secure electrical connections. Then, there are underground waterproof connectors, which are made of 100 percent sealant. These are used for outdoor pet containment systems, sprinkler systems, and low- voltage outdoor lighting. So choose the right connector based on your requirement. Check the connector’s features If you are using aluminum wires in an area where there is constant electromagnetic interference, you need wire nuts that can establish a connection undeterred by interference. Furthermore, the aluminum wire nuts will need to have special built-in features for the same.
  • Job benefits at Dollar General Corporation
    Being one of the largest growing American chains of variety stores, Dollar General Corporation has its own sets of company benefits for its employees. Some of them are listed below:
    • A job at Dollar General Corporation entitles the employee of health and welfare benefits. Dollar General Corporation offers multiple comprehensive plans that have varying levels of coverages based on the employee’s needs. Dollar General also contributes toward these benefits, one of which aids their employees to afford health insurance at affordable costs.
    • Employees with full-time positions and designated part-time positions that have averaged over 30 hours a week are qualified for medical, dental, vision, short term and long-term disability, life, critical illness, accident, hospital confinement, and prescription insurances. These employees are also entitled to medical care and dependent care flexible spending account and also health savings account. They also cover for business travel accidents.
    • Dollar General Corporation runs an Employee Assistance Program (EAP) which offers all its employees with 24/7 access to licensed clinical professionals and community resources that provide them with a workable solution to personal challenges.
    • In the name of compensations, rewards, and work benefits, jobs at Dollar general have a competitive base pay, annual bonus opportunity, service award recognition program, vacations, paid holidays, and a non-smoking environment.
    • The retirement savings plan of Dollar General includes 401k savings and retirement plan. It works in such a way that the employee contributes (up to) 25% of its pre-tax income to which Dollar General offers a dollar for dollar program. The employees can choose as to how they plan to invest their contributions. Moreover, they also offer a variety of wellness resources which include budgeting assistance and accessing an economical health coverage.
    • Their “Better Life Wellness Program” intends to help employees at Dollar General to take control of their health and emphasize on preventive measures to maintain a healthy lifestyle.
    To avail the benefits mentioned above, an employee at Dollar General should meet certain eligibility requirements.
  • Best down-filled quilted jackets for men
    Nothing can beat a good quilted jacket, whether it is for casual wear or spring wear. They are known by different names like puffer jackets, down-filled jackets and quilted jackets for minor modifications in their insulation. There are many quilted leather jackets available for purchase varying in insulation, color, and weight. Quilting is nothing but decorative stitches with multiple layers of fabric. A padding layer is provided between these two layers. It is this padding layers that provides a three-dimensional look on jackets that have quilting and diamond shapes. Let us take a look at some of the best quilted or puffer jackets available for men. Arc'teryx Cerium LT Hoody Weighing 10.8 oz., Arc'teryx provides effective insulation along with a premium feel. They are a built expensive but at the same time look the best among all the quilted jackets. The closest competitor is the Patagonia when it comes to looks. Cerium LT is a flagship product among jackets and weighs the least. A Cerium LT hoody costs around $379. Feathered Friends Eos Weighing around 10.6 oz. Feathered Friends provides the best warmth to weight ratio. This is a jacket for serious outdoor people. Although they aren't marketed to that extent, Feathered Friends are still considered top notch when it comes to their range of quilted and puffer jackets. The only drawback that they aren't ranked first is their limited availability of colors. A Feathered Friend EOS costs around $309. Rab Neutrino Endurance Weighing around 22.4 oz., Rab is a perfect outdoor jacket with real heavy down fill. The jacket has a 30D Pertex shell which gives a quality feel along with good resistance to weather. The only downside could be the same heavy down fill which makes the jacket a little heavier when compared to other jackets in the same league. The Rab costs around $375. Mountain Hardwear Ghost Whisperer Hooded Ghost Whisperer is a very lightweight jacket for incredible warmth. The jacket weighs around 7.7 oz. with a fill of 2.8 oz. The ghost whisperer comes with optional hood, two side pockets, and a side hem cinch. It is an ideal jacket for minimalist backpackers and climbers. The only drawback of this jacket is, ghost whisperer won't stand up to harsh weather and might wear out. Ghost Whisperer is certainly not a jacket for daily use. The zipper that comes along with the jacket is a little flimsy and can be a disappointment. The jacket costs around $350.