How Contact Lenses are Made

while they may seem uncomfortable to non-contact wearers contact lenses are amongst the most advanced and successful technologies out there they are flexible don't get in the way and are more affected than glass and reduce the possibility of infection but how does such an incredible and advanced thing get made let's find out getting the right raw materials nowadays there are a few types of lenses to choose from and these mostly different material used to make them for example there are the most common hard lenses which are made of poly hema plastic a relatively elastic that tough material doesn't get damaged so easily then there are soft ones made like a gel like plastic which are cheap disposable and more comfortable they are even midway lenses nowadays which are made of a combination of these materials and while all of them have their importance today we're going to be talking about the first kind hard lenses now the raw material for these lenses is brought to the factory in form of a long rods roughly the diameter of the largest lens these rods are actually already colored blue brown white or any desired color that our user may desire and while the exact chemical combination might differ from company to company all of them are supposed to have uniform optical qualities the ability to retain their shape and composition and finally the ability to absorb water which is an essential for the lens to be able to stick to the eye this brings us to the manufacturing stage whose first step is step one prep now it's no secret that each set of lenses is unique to the wearer which is why you can't just go and order a standard factory lens instead for each set of eyes unique measurements are supposed to be taken that are crucial to the size shape and other properties that make the lens usable these measurements include stuff like eye thickness the size of the cronia the exact optical number of the eye and even any tiny imperfections that might be on the eye surface all of this is done by optometrist with a specialized equipment and once the prescription has been recorded with all the color and material preferences the information is sent to the factory which is where we move on to the next step step 2 compulsorize lathe at this stage all the prescription data and any other requests are fed into a computer that controls any and all automatic lathe machines after that the operator grabs the polyhema rod of the desired color and affixiated it to the length and preparation for the machine the next step is to cut the inside the curve of the lens into the material this is done by rotating the lens a bit over 6 000 revelations per minute and bringing it to under the next industrial diamond bit this ensures that a the lens is cut without any imperfections and b it is cut super fast and once the lathe has cut the groove it does another pass to remove any remaining abrasions finally for this step the polymer bit is cut off from the rod and taken to the next step step 3 polishing the insides now this step is probably the most crucial since this side of the lens that will be in the contact with the eyes so it has to be absolutely perfect to ensure that the wearer does not face any discomfort while wearing or taking off the lens as for how it's done the individual bit from the previous step is now glued to another machine where a micro abrasive paste is put into the inside then the machine places the lens on top of a rounder polisher where spins around fast enough to smooth out the surface and once those insides have been inspected and clean we move on to the next step step 4 waxing and leaving the outside this step is pretty much a reputation of the inside machining but for the outside only this time since the inside has already been made to fix it it is glued to the lathe using a special warm wax then it is pretty much the same diamond drill bit two passes one to achieve the desired thickness another to achieve the curve and vloa the lens is part of the lens is complete finally the entire bit is machined on one last time to bring the lens diameter to match the wearer's cornea which is done using the same diamond bit and the now separated lens is brought to the next stage which is step 5 polishing the outsides just like the inside the time for the outsides are coated for the abrasive paste combined with some oil and since it's a convex shape instead of a convex one instead of a round polisher a fine polystyrene cotton ball is used for the final step after that a worker then polishes the rim of the lens completing the fabrication after this comes the longest and probably the most boring part of the lensing making process step 6 hydration now as slow as the process is without proper hydration a lens is basically unusable why well you see the polymer of the lens is actually made out of a pretty dry and hard metal material so to make it actually usable the lens has to be soaked in water for a whole 24 hours before the lens becomes both flexible as well as larger in size this results in characteristic sticky smooth and rubber like lenses most of us are very familiar with and once the desired material state and size are achieved we move on to the second last step step seven testing this is also very and a very important step as if it's not tested properly a slight error can cause long-term consequences for the wearer as a result before the lens is deemed complete it undergoes a few testing methods ranging from a simple visual inspection a test using an optical telegrapher to verify the uniformness of the optical power as well as the shape of the lens and finally two simple tests one to measure the exact power of the lens and a frontal focal meter test to verify the lens precision and once a bat successfully passes the test it leads the manufacturing stage onto the last one step 8 finishing touches at this level all the lenses are separated into the original pairs which each pair being into containers filled with a salt solution which not only keeps the lenses wet but also makes sure that no germs or other microfibers collect on them these vials are then preserved for either shipping or kept in storage until they are needed and as last preservation measure before they are sent away they are all sterilized at 121 degrees centigrade for 90 minutes before being sealed with a plastic seal and an aluminum cap and that's basically the entire process from start to finish each individual lens takes almost a whole day to make but if you include the 24 hour hydration it only takes 15 minutes from raw material to the finished lens added the fact that due to their sizes lenses are made in batches of hundreds of a time it's not a surprise that mo contact lenses can push out a thousand complete contact lenses a day making the entire process definitely worth it let's take a look at the history now history contacts have actually been around for almost the same time amount that glasses and other eye treatments have believe it or not in fact the first contact lens was made all the way back in 1887 by german philosophers adolf flick but back then those lenses were also just made of glass fit over the whole eye and were ridiculously and uncomfortable to wear it was only in 1912 that carl zeiss was able to make the first modern glass concealed lens which is called that because it fits over the cornea of the lens and the eye instead of the whole thing like the previous lenses and since then other materials like click the glasses and plastic have also been introduced giving users the option to have a whole platter of lenses to choose from click one of the two videos on your screen right now [Music] you

Channel: How It's Made

Views: 30,124

Keywords: how its made, how to make, how it's made full episodes, how its made season, discovery, how stuff works, discovery channel, contact lenses, contact lens, contact lenses for beginners, how contact lenses are made, how it's made contact lenses, hard contact lenses, how soft contact lenses are made, rgp contact lenses, contact, how are contact lenses made today, how it works contact lenses, how to put on contact lenses, what are contact lenses made of, dr eye health contact lenses

Id: DZJpPduIc4w

Length: 7min 49sec (469 seconds)

Published: Thu Aug 04 2022