What are eye-glasses?
Eyeglasses also are known as spectacles are glass or plastic lenses compiles up in a comfortable frame that helps in covering the vision fields for any duration of time. It is a tool used for vision improvising, eye protection, and curing certain vision defects.
Types of eye-glasses:
Corrective lenses:
Corrective lenses cure the refractive errors by bending the incident rays entering into eyes according to the requirement of the disorders like myopia, hypermetropia, or astigmatism. These disorders are caused due to alteration of near and distant focus. Corrective lenses help in adjusting the image exactly at the focus of the retina. Improvising the vision quality of the wearer, it also helps them to get rid of eye strain, headaches, eye fatigue, and eye squints.
Further, it consists of the following categories of lenses:
- Adjustable-focus eyeglasses – They are used in place of Bifocals and Trifocals and also in providing cheaper single-vision glasses. They are cheaper because they need not be custom-manufactured for every person.
- Pinhole glasses – These vision aids do not use any lenses. Instead of adjusting the incident rays on the focus of retina, they create a diffraction-limited system that increases the depth of the field. Due to many drawbacks like its less effectiveness, these are not prevalent for everyday use.
- Reading glasses – These glasses are designed for providing a safe reading to us with simple lenses of equal power. They are a very cheap and easily available solution of safeguarding your eyes and did not require the prescription of an expert.
- Single-vision lenses – These are built for the people with presbyopia (inability to focus clearly on closer objects at old age) and hyperopia (inability to focus on closer objects at the initial level and at severe level patient can’t focus on both closer and distant object) since they have a uniform refractive index.
Safety:
Safety glasses act as a protective shield that prevents our eyes from various harmful elements affecting them like blue-rays, dust, etc. Mostly, construction workers, factory workers, mechanisms, and lab technicians use these glasses to protect their eyes from flying debris or hazardous splatters such as welding flash, blood, or chemicals. These glasses could also be used for protection against the blue rays emitting from digital screens.
Sunglasses:
Sunglasses are formed for the purpose of protection against ultraviolet light and bright light. Photochromic lenses are used in sunglasses which are photosensitive and thus become dark when UV rays hits on the glass surface. Further, these glasses help blind people to hide their eyes for cosmetic reasons.
Mixed double frame:
These are flipping glasses which consist of one fixed glass and one mobile glass connected in a single frame by four-bar linkage. By using these lenses one may deal with the issue of presbyopia in which one has both near-sightedness and far-sightedness, so that in case you want to see the closer object you may use myopic lenses and in case you want to see far objects you may uplift the front glass and use hypermetropic lenses.
Magnification glasses:
These glasses are used to provide a magnified view to the people dealing with vision impairments. However, they could also be used for specific occupational demands. They usually consist of small lightweight telescopes behind the regular lenses. The telescope could be installed on existing glasses or could also take the form of self-contained glasses.
Significance of eyeglasses:
- Eyeglasses could be managed to wear easily by both adults and children.
- They are not as costly as lenses and surgeries.
- They are effective and cures the vision defect up to 0.50 dioptre of the desired correction.
- They do not need much care and complicated management and are very easy to handle and apply.
- They can not cause any eye infection or damage since they are a certain distance away from eyeballs.
- They are easily available and their power can be adjusted easily by the specialist according to the eye’s requirement.
Disadvantages of eyeglasses:
- Eyeglasses are not acceptable in many places like in active sports and fire-fighting.
- Eyeglasses are not comfortable many times. Especially during hot and humid climate they become very annoying and inconvenient while resting on the nose.
- If they are not kept at a suitable place and by mistake leftover carelessly, they can be broken or lost.
What is the Contact lens?
Contact lenses are ocular prosthetic devices used for vision correction and in some cases for cosmetic or therapeutic reasons. These are very thin lenses also known as contacts and placed on the surface of eyes. Most of the people wearing contacts are mainly fascinated by the aesthetics and cosmetic factors. These are specially designed for the people who are not comfortable with the eye-glasses.
Types of contact lenses:
- Soft contact lenses – they consist of soft and flexible plastic that allows the passage of oxygen through the cornea. They are more comfortable and easily adjustable than rigid permeable lenses. They contain silicone-hydrogels which allows more oxygen to enter the eye while one wears it.
- Rigid Gas Permeable contact – they intend to give a clear and crisper vision. Initially, they seem less comfortable than soft contact lenses but within a few weeks, one would become used to it. They are long-lasting and hence less expensive than soft contacts in terms of their life.
- Extended wear contact lenses – they are usually a kind of soft contact lenses since they are made up of soft plastic to allow the passage of oxygen through the cornea. The special feature of these contacts is that they are made for the purpose of long-term wearing. You can wear it maximum till 30 days continuously without removing according to its range. However, this continuation depends on the lens type and eye’s toleration calculated by an expert.
- Disposable contact lenses – they are meant for using one time only and then discarding. However, their usage period could be extended by the prescription of a doctor.
Significance of contact lenses:
- Contacts allow a natural field of view since they cover the eyeballs appropriately and thus move with the eye.
- Since contacts are frameless, they do not obstruct the vision fields and reduces distortions.
- Unlike eyeglasses, they neither get fogged up nor gets spotty during humid weather.
- Contacts provide more real and natural sight to the wearer as compared to eyeglasses
- Contacts are acceptable to be worn while playing sports, unlike eyeglasses.
Disadvantages of contact lenses:
- Contacts take much time for fitting and adaptation.
- They require great care to be taken by the patient while handling.
- They could be worn for a limited duration of time depending on its type.
- They could be broken or lost easily if not handled with care.
- It takes a heavy cost of maintenance.
- They need a long hygienic procedure otherwise could cause lens infection.
This article is an open study of both eyeglasses and contact lenses. Both the pros and cons are listed here. Now, you can decide according to your eyes that among the two which suits you the best
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