USE OF FRESNEL LENS AS PHONE MAGNIFIER

 

USE OF FRESNEL LENS AS PHONE MAGNIFIER

By Tanushree Mazumder,1st year student, Pailan Collage of Management & Technology MAKAUT.

 
ABSTRACT:
OBJECTIVE:
·     Use of FRESNEL lens as phone magnifier for safe comfortable reading with low cost.
·     Attract attention for research and development in this regard.
·     Encourage & educate about eye health, especially among young generation.
 

INTRODUCTION:
Due to COVID-19 use of digital platform has increased, which is directly affecting eye health. Extensive research has been conducted in this area. One finding which seems to be mentioned everywhere is `blue light’. This light which is emitted from our phone , tablets & laptops , sadly it has been found to have negative effect on our eye health. Studies suggested that it has “a potential to lead a macular degeneration”, by passing the pupil & cornea to beam directly into the retina. The blue light is thought to affect central vision as it kills off photoreceptor cells in the retina. Unlike some other cells in our body, once these cells die, they cannot regenerate. This means that any damage done to them is permanent.
AIM- By magnifying the image with help of Fresnel lens coated with antiglare and anti reflective coating will protect eye.
WHAT IS THE BACKGROUND- I recently came across a number of arguments for or against the introduction and implementation of digital learning and work. In theory, digital learning appears to be something extremely beneficial to all. But along with many advantages it brings some health hazard, which is needed to be taken care immediately.
KEY WORDS- Fresnel lens, Magnification.
 
INTRODUCTION:
PHONE MAGNIFIER-Screen magnifier-smart phone magnifying glass-enlarge screen- Magnifier with protective coating will prevent damaging rays to enter eye.
MAGNIFICATION, in optics, is size of the image relative to the size of the object creating it.
·     Linear (sometimes called lateral or transverse) magnification refers to the ratio of image length to object length measured in planes that are perpendicular to the optical axis. A negative value of linear magnification denotes an inverted image. 
·     Longitudinal magnification denotes the factor by which an image increases in size, as measured along the optical axis. 
·     Angular magnification is equal to the ratio of the tangents of the angle subtended by an object and its image when measured from a given point in the instrument, as with magnifiers and binoculars.
 
REASONING:
FRESNEL LENS: The thin piece of plastic is used as Fresnel lens. It is flat on one side and ridged on the other. Fresnel lens we used first in the 1800s as the lens that focuses the beam in lighthouse lamps. The basic idea behind a Fresnel lens is simple. Image taking a plastic magnifying glass lens and slicing it into hundred concentric rings (like the ring of a tree). Each ring is slightly thinner than the next and focuses the light toward the center. Now take each ring ,modify it so that it’s flat on one side, and make it the same thickness as the others. To retain the rings’ ability to focus the light toward the center, the angle of each ring’s angled face will be different.
1. The number of rings per inches controls the resolution and effective magnification up to high as 19X for ophthalmic purpose. It is produce in an expensive manner in almost any size. A Fresnel lens magnifier is a thin plastic in which the surface is reproduced in a series of rings or zones.
2. They are inexpensive. They are convenient and easy to use- flip them up when not to using them, bring them down in front of your glasses when you are using them. This is especially helpful if the person has strong myopia (nearsightedness) or astigmatism. Some advantages of clip-on loupe are: Loupes are magnifying devices. A clip-on loupe attaches to glasses, and allows a person to be hands free while viewing text, the computer screen or other work. Strong loupes (over +10D) can be used only with one eye; where as weaker loupes can be used for both.
3. Amount of add needed depends on the accommodation and the reading distance. Used for near work Magnification is 1/4th the power of the lens. Reading distance is calculated by 100 divided by add, given as an add to the best distance refraction high plus reading glasses to magnify the images.
4. A spherical lens maybe used to reduce lenticular distortion, when binocular correction is needed. If the patient is monocular, the poor eye may be occluded if it improves the functioning. However usually great add is required that predicts as the patient also has reduced contrast sensitivity. Reading add can be predicted using the Kestenbaum rule i.e. the amount of add needed to read 1M print is the inverse of the visual acuity fraction.
5. Disadvantages:
o  Higher the power, closure the reading distance.
o  Closure reading distance cause fatigue and unacceptable posture. 
o  Patient with eccentric fixation are unable to fix through these glasses.
6. Advantages: 
o  Hands free.
o  Field of view larger when compared to telescope. 
o  Greater reading speed. 
o  Can be given in both monocular and binocular forms.
o  More portable.
o  Cosmetically acceptable.
 

CONCLUSION:

Thus using such device will help to reduce many unnecessary health complications like 

·    Blurred vision
·    Headaches
·    Pain in shoulders and neck
·    Dry and red eyes
·    Difficulty in concentrating
·    Making errors
 
REFRENCES: 
1.F.Bernardini, J.Mittleman,H.Rushmeier, C.Silva and G. Taubin, “The Ball-Pivoting Algorithm for Surface Reconstruction,” IEEE Trans.
2.https://slideplayer.com/slid/3808714/
3.Slicing.com/magnifying-glass-work-4567139.