Standards for Contact Lenses
The ISO is the International Organization for Standardization. They set standards for everything from construction materials to medical devices. Most ISO standards related to contact lenses are set by the ISO/TC 172/SC 7 Committee that is dedicated to ophthalmic optics and instruments. These standards are followed by most contact lenses manufacturers as well as suppliers. Industry standards like these ensure that everyone makes products that are safe, reliable and compatible with each other to as great a degree as possible.
What are the main standards for testing contact lenses and contact lens products?
ISO Standards for Contact Lenses
ISO 14534 is the standard for contact lenses. ISO 8321-1 gives the specifications for rigid contact lenses. ISO 11539 was the standard for classifying contact lenses and the materials used to make them, but this standard was replaced by ISO 18369-1.
- ISO 14534:2011 - Contact lenses and contact lens care products
ISO 14534:2011 - Ophthalmic optics -- Contact lenses and contact lens care products -- Fundamental requirements
ISO 8320-2 was the original standard for the vocabulary used to describe contact lens care products; ISO 8320-2 was replaced by ISO 18369-1. ISO 9337 was the standard for measuring the back vertex power of contact lenses, but this standard was replaced by ISO 18369-3.
ISO 18369-4 replaces ISO 9913-1 for determining the oxygen permeability of contact lenses using the FATT method, sometimes described as how much air the eye gets through the contact lenses. ISO 18369-4 also replaces ISO 10340, the method of measuring the extractable substances from contact lenses.
ISO 9338 was the standard for determining the diameter of contact lenses. This standard was replaced by ISO 18369-3 in 1998.ISO 9914 was the method used to determine the refractive index of the materials used to make contact lenses. ISO 9914 was replaced by ISO 18369 Part 4.
ISO 9339 was the standard method for determining the thickness of contact lenses; ISO 9339 was replaced by ISO 18369-3. ISO 10339 was the test method for determining the water content in hydrogel contact lenses. For reference, hydrogel is a soft silicone that allows oxygen to pass through it. ISO 10339 was replaced by ISO 18369 part 4.
ISO 11978 describes the information contact lens manufacturers and contact lens care products must provide to customers.
ISO 8599 was the standard of light transmittance by contact lenses; this standard was replaced by ISO 18369-3.
ISO 11985 measures the aging of contact lenses as they are exposed to ultraviolet light and visible light. ISO 12864 is the standard for determining the scattering of light by contact lenses.
ISO Standards for Products to Take Care of Contact Lenses
ISO 11986 is the standard for contact lens care products. It includes information such as the determination of preservative release.
ISO 11980 gives guidance for clinical investigations for contact lenses and products used to care for them.
ISO 14729 lists the requirements and test methods of products used for microbiological management of contact lenses, essentially those products that prevent bacteria and fungus from growing on the contact lenses. Hygiene for contact lenses is critical because eye infections can lead to blindness.
ISO 13212 outlines the methods for determining the shelf life of contact lens care products. This standard was published in 2011.
ISO 11981 describes the methods used to determine the compatibility between lens care products and contact lenses. While the lens care products need to remove dirt, salt left by human tears and debris, the lens cleaner should not harden soft contacts. The ability of lens cleaner to kill pathogens is covered by ISO 14729.
ISO Standards for Contact Lens Testing
Bio-compatibility can be described as how well the body tolerates a material or object. ISO 9394 describes how the biocompatibility of contact lenses is determined by placing contact lenses in the eyes of rabbits and using lens care products on those contact lenses. ISO 11979-5 sets the standard for bio-compatibility of contact lenses.
ISO 10343 is the standard for opthalmometers, devices that can measure the curvature of contact lenses. ISO 15004 gives the functional requirements and test methods for ophthalmic instruments like opthalmometers.