Process Essay: Seeing Through The Lens

The tear layer has less effect on contact lens power, if lens is in perfect alignment onto the cornea. The degree of clearance of the lens enables the tear film to have a power effect on cornea/tear/lens system. Inadequate watery layer in the tear film causes dry eyes. As such the contact lenses become uncomfortable to wear.

The cornea, a section of the protective and supportive part of the eye, refracts light to make it focus more on the center of the iris. In the center of the iris is an opening known as the pupil. (Mcdevitt) The iris also regulates light intake by reducing or increasing the size of the pupil. Behind the pupil is the lens of the eye. The lens keeps the light the eye is receiving focused on a specific point on the retina called the fovea. (Starr) The retina is the area in the back of the eye where all of the photoreceptors are located, neuro receptors that are sensitive to light. The fovea is the part of the retina that has the highest preponderance of photoreceptors. (Sung) The lens of the eye also integrates information by determining where the eye is focused. In order to keep the light that bounces off of an object focused on the fovea, the lens must change shape based on distance. The shape of the lens is controlled by a group of ligaments called the ciliated bodies. When the ciliated bodies tenses it causes the lens to be more round allowing the eye to focus on light coming from objects closer to the eye. When the ciliary body relaxes it allows the lens to become more flat allowing the eye to focus on objects further away. (Sung) All of the processes of the eye mentioned up to this point do not directly cause transduction; however they are another illustration of the way that the body performs integration of sensory

According to the dictionary definition, a lens is an optical device that is used to focus or disperse light beams by the means of refraction. Moreover, the lens is made up of transparent material such as glass or clear plastic which allows the light pass through and interacts with the medium without it being absorbed. A lens is typically made to focus light unlike prisms which refracts it to show the different band of wavelength.

The cornea which is the part of your eye where the contact lens will sit, requires oxygen, if you were to get contacts without a proper contact lens fitting it is possible that the lenses be too tight, this would be like suffocating your cornea, leaving it with little to no oxygen. Wearing a lens that doesn’t fit your eye properly could lead to neovascularization. Dr. Bishop from Alberta, Canada puts it this way, “When the cornea is deprived of enough oxygen the endothelium pump loses efficiency and is unable to maintain the relatively dehydrated state of the corneal tissue, and therefore it begins to swell. When the decrease in available oxygen becomes chronic, the cornea responds by allowing tiny new blood vessels to grow. This is corneal neovascularization.” This is the body’s defense mechanism to bring oxygen to your eyes. If the blood vessels aren’t caught early enough it’s nearly impossible to reverse the effects. Another effect of depriving your cornea of oxygen would be swelling. Your cornea will swell because it is storing water, this would lead to an even tighter fitting contact. Someone who’s experiencing a swollen cornea could be seeing halos around lights, distorting their

Accommodation and convergence allow us to see objects clearly both near and far without needing double vision. Accommodation is the ability to focus on close vision. Convergence is the movement of the eyes when focusing on close objects. Emmetropia is normal eyesight. Myopia is nearsightedness. It is when you have too much focusing power. Light focuses in front of the retina and make the far vision blurry. Hyperopia is farsightedness. This is when the eye is short and not enough focusing is happening. Light coverage is behind the retina and causes close vision to be blurry. Having liquid in your eyes, some of it drains into holes and then into lacrimal sac then going into the nasolacrimal duct, and into the back of your nose and/or throat

The cornea is the outermost layer of the eye. It is smooth, clear and referred to as the window of the eye, because the cornea allows light to pass through to the eye. The cornea also helps to shield the eye from harmful matter, such as dust and germs. It is responsible for about 65 percent of focusing power for the eye. When light enters through the cornea, it bends and refocuses the light to the retina, which begins translating the light into vision. In order to see clearly, the light rays must be precisely focused when going from the cornea into the retina. An rregular corneal surface is common and may be caused by a number of different reasons, such as genetically inherited, injury, disease or natural occurrences.

Retinal illuminance is a key factor in the sharpness of someone’s vision and in turn, their visual acuities. If not enough light is reaching the retina, the human brain cannot distinguish between certain details in a word, much less a letter. The cataract, depending on where it is located in the lens, causes light to bend around it in an effort to reach the retina with full illuminance. This allows the light to reach the photoreceptors of the retina, which can then be transduced into a chemical signal that follows its pathway to eventually, the visual cortex. This results in an image perceived by the brain. However, if the cataract is big enough, it can prevent the light from reaching the photoreceptors and disrupting the whole process of the visual system. Therefore, it is imperative that the lens be free of noise in an effort to transduce as much light as possible to the retina. This means removing the cataract, thereby increasing a person’s visual acuity.

Nearsightedness, or myopia, is when objects far away appear blurred and objects nearby appear normal. This occurs due to a curved cornea or long eyeball. For example, a long eyeball will result in light rays improperly focusing on the retina. However, heredity and vision stress also contribute to myopia. There are certain lifestyle habits and environmental conditions which exacerbate myopia. For example, reading in poor light or watching a TV or computer screen in a dark room. Diabetes can also experience myopic like symptoms due to low blood sugar levels. Myopia can be conditionally corrected through proper eyeglasses or contact lenses. However, wearing glasses for the rest of you life can be inconvenient and uncomfortable. According to the AOA, Lasik surgery can cure nearsightedness through reshaping the cornea by removing select inner layers of

There are many skills one must obtain when working on the hill. Having superb writing skills is critical. Writing, specifically on behalf of someone else is a difficult task, because you have to think, interpret, and write in a tone that Harry Reid would himself. Written content on behalf of the elected official must be presented clearly and professionally. The reader will gain an impression of the elected official based off of how well they write. If the concept is written in a confusing way the message will fail to get across. Pieces such as congressional statements, press releases, and constituent letters must be written with precision given that if there are multiple spelling and grammar errors it will come off as if the elected official is uneducated. May it be on behalf of an elected official, or as simple as writing an email to a coworker, poor writing skills create bad impressions and result in negative reactions.

Unfortunately for them, wearing contact lenses either for long or short term has potential to cause serious and permanent vision damage. In other terms, you are inserting a foreign piece of plastic on top of your eye. This can cause things like infections, bacterial irritation, altered corneal thickness, corneal ulcers and micro-cysts if you aren’t careful. Research has proven that 1 in 2000 people who regularly use contact lenses are susceptible to vision-threatening infections, while just 1 in 10,000 LASIK recipients experience

The structure of the eye has a ciliary body is an extension of the choroid layer.  It functions with the suspensory ligament to attach and support the lens.The aqueous humor is a watery material between cornea and lens. The vitreous humor is gelatinous material within the eye.Focusing by the lens is called accommodation, focusing in humans is done by changing the shape of lens with ciliary muscles.  These muscles are part of the ciliary body. The ciliary muscles surround the lens they are attached to the lens by suspensory ligaments. When distant objects are viewed, the ciliary muscles relax, putting tension on the suspensory ligaments. The taut ligaments pull the lens, causing it to become thinner. Nearby objects cause the ciliary muscle to contract, reducing the tension on the suspensory ligaments and allowing the lens to assume a thicker shape. The cornea bends light but the lens finishes focusing. As a person ages, their ability to focus their lens decreases.  Glasses can correct for this loss of focusing ability. Focusing occurs when the eye is too long and the plane of focus is in front of the

Myopia (nearsightedness) is a common vision condition in which you can see objects near to you clearly, but obects farther away are blurry. Nearsightedness may develop gradually or rapidly, often worsening during childhood and adolscence. Nearsightedness tends to run in famillies. A basic eye exam can confirm if your nearsighted. you can easily correct the condition with eye glasses or contact lenses. Another treatment option for Myopia is surgery. The underlying cause is believed to be a combination of genetiv and environmental factors. Risk factors include doing work that involves focusing on close objects, greater time spent indoors, and a family history or the condition. The underlying Mechanism involves the length of the eyeball being too long or less commonly the lens being too strong. It is a type of Refractive Error.

There are many individuals who suffer from eye conditions that force them to wear contact lenses and glasses as means of correcting their vision. In such cases, the problem is usually with the shape of the lens in the eye, and the used of an extra lens makes it much easier for people to focus.

One of her style using contact lenses in her video ‘Bad Romance’ for giving larger & more child-like effect to eyes becomes controversial. Her fans are copying the big eyed effect but it leads to eye infection, damage to vision & even blindness.

Contents Introduction 3 What is Crystalline Lens? 4 Structural of Crystalline Lens 4 Function of Crystalline Lens 4 Connections between Refractive Error and Crystalline Lens 5 Myopia 5 What is myopia? 5 What caused myopia? 5 How to solve the problem. 5 Hyperopia 6 What is hyperopia and what caused it? 6 How to solve it? 6 Most hyperopia patients will cured by them getting older. 6 Presbyopia 6 What is presbyopia and what caused it? 6 How to solve presbyopia? 6 Conclusion 7 Bibliography 8