By Rebecca Layzell 8D

An optician is a man/women who tests your eyesight and looks for whether you need glasses or not. The optician is trained to give prescriptions for the eye and isn’t considered a person to take medical tests apart from on the eye. They are also trained to recognise changes and problems within the whole eye, particularly the retina. Certain changes can relate to other diseases, e.g.. Diabetes and high blood pressure They use many items in their equipment. They may use a Snellen chart, which has letters that get smaller and smaller.This is used to test visual acuity, or how good your eye sight is. A lensometer is another piece of equipment used by opticians to measure the correct prescription to give to one in their glasses. Also used to get the correct mounting of the lens and to verify the strength of the lens or contact lens. Sometimes if you have a cataract then they will shine a light in your eye to look at the cloudiness of the lens and to see whether they need their lens replaced with a fake one. This is how long and short sighted people see and below is what it should look like when you have perfect vision.

Opticians use light to be able to visualise the back of the eye; the retina. They may use an ophthalmoscope or a slit lamp. This is a Ophthalmoscope. It uses a light source,a series of lenses and a small mirror to enable the observer to see an image of the retina.

As well as the ophthalmoscope, doctors use a variety of other pieces of equipment with light sources. These include an otoscope which is used to look into the ear, lights to visualise the throat and also numerous endoscopic instruments that can be passed into different areas of the body, e.g. into the nose and throat, stomach and bowels as well as into body cavities. They can be used for investigations and also to carry out surgery. The light enables the doctor/surgeon to see clearly into an otherwise dark space. An Otoscope is a piece of equipment used to examine the ear. It consists of a head and a body. The head is the part which shines the a light on the point and on the flat edge there is a magnified glass used to give a more focused image of the ear.

Mining is a job which consists of extracting minerals and precious metals from different types of rocks and ore on cliffs, in caves and many other difficult areas. The natural process of mining creates a potential negative impacts to the environment though and has many potential risks along with this job such as cliff falls and caving yourself in. They use light to be able to see what they are doing and to be able to do the job, they also use this to see the risks and dangers that could be lying ahead. One piece of equipment they use is called a carbide lamp. It is originally known as a which burns acetylene to cause a reaction called calcium carbide with water. They are used to illuminate buildings and still use them in lighthouses today. Early cavers used to use these pieces of equipment before light weight equipment came into use, they would usually wear them on hats or around their necks on their garments.

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