Types of lenses It is essential that all people have a basic understanding of lenses. Eventually, all people will need reading glasses if they didn't need them from the beginning of their lives. The user must have a general understanding of what is available and the different characteristics of some basic lens types. Furthermore, understanding your needs is necessary to avoid being steered towards a more profitable sale for the optician paid on commission. Spectacle lenses are one of many different types of lenses. The lenses used in glasses can fall into some specific categories such as: single vision, bifocal, trifocal and progressive types. As an optical lab manager and technician for the past 15 years, I see and use these various types of lenses daily to fill prescriptions and user needs. The position of laboratory manager also gives me specific knowledge of remakes produced by opticians who are most interested in selling what they earn the most or from which they get the most profit. It is these factors that make it essential for eyeglass users to understand how each type of lens might affect the usefulness of wearing eyeglasses in their individual practice. Lenses are divided into two main categories: monofocal and multifocal. Single vision lenses are used to correct focal point problems within the eye, as well as distortion problems. To accomplish this task, single vision lenses are classified into lenses with spherical power and lenses that also have cylindrical correction. Most end up being a combination of focal point and distortion correction. Spherical lenses are further divided into plus and minus correction depending on whether the patient... middle of paper... r years will, at some point, need glasses for near vision correction. This is achieved with any type of single vision, bifocal, trifocal or progressive. All of these types of lenses have specific purposes and reasons for their use with advantages and disadvantages for each design and purpose. It is important that you understand your options to make a wise choice and best meet your needs. The user cannot always assume that the optician or salesperson has a full understanding of the user's specific needs when dealing with a commission or bribe. With this fact in mind, it is always best for the user to have a basic understanding of the different types of lenses available. Reference The Eye Info Network. (2011). Choice of glasses lenses. Retrieved from All About Eyeglasses website: http://www.allabouteyeglasses.com/eyeglass_lenses.htm