Chosen Object - Contact Lenses.

Web definitions of Contact Lenses

• contact: a thin curved glass or plastic lens designed to fit over the cornea in order to correct vision or to deliver medication                  

• A contact lens (also known simply as a contact) is a corrective, cosmetic, or therapeutic lens usually placed on the cornea of the eye             

• A thin lens, made of flexible or rigid plastic, that is placed directly on to the eye to correct vision, used as an alternative to spectacles, or, if coloured, to change one's eye color cosmetically

• (Contact Lenses (CL)) All aspects of contact lens therapy inclusive of keratoconus and postsurgical

        (Contact lenses) Lenses that sit directly on the surface of the eye.

Small, thin removable plastic lens worn directly on the front of the eyeballs, usually used instead of ordinary eyeglasses for correction or protection of vision.

con·tact lens
noun 
contact lenses, plural
A thin plastic lens placed directly on the surface of the eye to correct visual defects

Contact Lenses

A contact lens (also known simply as contacts for a pair) is a corrective, cosmetic, or therapeutic lens usually placed on the cornea of the eye. Leonardo da Vinci is credited with describing and sketching the first ideas for contact lenses in 1508, but it was more than 300 years later before contact lenses were actually fabricated and worn on the eye. Rigid ones were produced and marketed first. Modern soft contact lenses were invented by the Czech chemist Otto Wichterle and his assistant Drahoslav Lím, who also invented the first gel used for their production.

The text in the centre is from the english dictionary of the definition of contact lens and then the information below is what i was able to get about contact lenses on Wikipedia, this was the first step to getting an insight into these objects, they have loads of different variations and ways that they can be made and seen, and the process can be rather quick to do, ill now look into the creating processes on how they have been made

Process of creating contact lenses

source from tv show "how its made"

 

Contact Molding

The most common technique used to manufacture contact lenses is molding. The raw material for the contact lenses are injected or poured into a mold. The lens is then formed in the mold to a specific power, diameter, curvature and edge shape. The contact lens is also cooled, spinned, and polished to form the finished product.

this can be seen in the video above which is from a TV show called "how its made" this appears to be how most contact lenses are made these days due to how many you can make and the quick process, you can also easily select the colour and size and create them continuously due to the mold being ready set for you, this makes life a lot easier on the factories and then allowing you to be able to create bulk, increasing the income for the manufacturers 

Contact Lathing

Another process used to manufacture contact lenses is lathing. Contact lens blanks are punched out of strips of solidified raw material. They are then placed on a lathe and spun around at high speed. The shape, power, and curvature are then cut into the blank with a laser or diamond. The contact lens is polished while the lathe spins.

However there are still this process also, this is as well as the molding technique this is in the video above as well, this can then be changed to look at what is easiest to be created using the most out there technique. Factories will always have different techniques for different manufacturing and this will influence the quality of the contacts that will be created from. There is more then one company that can create contacts some of these are below...

Companies that make contact lenses:
ReNu
Sauflon Comfort Ease
Specsavers
EasyVision
Cooper Vision
Bausch


These are just some of the contacts that are made to help correct the damages in people eyes and to help them to be able to see a lot clearer without having to wear glasses.

Contact Spin Casting

Another process used to manufacture contact lenses is spin casting. The liquid raw materials are spun at high speed until they form the desired shape. They are then cooled until they solidify. The spin casting technique allows more water to be stored inside the contact lens. Up to half of a contact lens made this way will be water.

This method is not as popular as what you would find in the other ones, however it still works and can be found in some companies, but the most interesting thing about this is one is the method in which it gets designed due to the high powered machines which are used to spin them to the right shape, the contact lens spin casting method is a lot more difficult to create the lenses in mass production as it takes only slightly longer for each one, yet when creating bulk that soon adds up!  

Contact Finishing

Fine detail work is performed on each contact lens before it leaves the manufacturer. Each lens is "finished" by grinding it to fit specific characteristics of the eye. The contact lens is placed on a grinding machine where emery paper or a razor blade is used to trim it down. This work is often done by a computer.

The precision is impossible to achieve with a human hand so you need to be able to do it with a computer, that's the main use of how precise these have to be to be able to allow for every set of contact lenses to be made to precisely fit each customers eye shape and the right amount of vision they need to be corrected.