How are glasses made to a prescription?

1. Preparation

To start with the laboratory technician will enter the optical prescription of a pair of Glasses on a computer which then prints out a copy of any additional information required in the manufacturing process of these lenses.

3. Generating

Each lens blank is placed in a generator or grinding machine which grind the back of the lens into the correct shape.

4. Polishing

After the grinding process when the correct lens curve is generated, it is polished, bevelled and sterilsed using a variety of tools such as a fining (hand polisher) machine and soft sandpaper. During this process, the optical properties do not change. Modern machines have an auto-polisher integrated eliminating the need for a separate fining machine.

5. Edging/ Glazing and Assembly

An edge grinder grinds each lens into the final shape and puts a bevel on the edge so that it fits perfectly into the frame. A lab technician will then fit and assemble the lenses into the frame by hand.

This is the final stage in which the lenses are dipped in UV treatment and given a tint if desired before being placed in the customer’s Frames.

Common treatments include ultra-violent tints, scratch-resistant and reactive coatings such as a photochromic coating which causes the lens to darken when activated by UV light.

7. Quality control

To ensure that each lens meets the strict quality control guidelines at Feel good Contacts, they are given a thorough inspection before delivery. Not only will a visual inspection be carried out to check for dust or damage, but a mechanical inspection will also be performed to check that each lens meets the correct specifications. During the quality control process both frames and lenses are checked.