The ABDO Rule, designed by George Clayton and produced by the Association of British Dispensing Opticians (ABDO), is an essential tool for dispensing opticians. This specialized ruler is used to take precise measurements necessary for fitting and dispensing eyeglasses. It is particularly vital for students and professionals in the field of ophthalmic dispensing, as it is a required item for courses such as the Foundation Degree in Ophthalmic Dispensing and the Fellowship Dispensing Diploma at ABDO College
The ABDO Rule allows opticians to measure various critical dimensions of eyeglass frames and lenses. These measurements include the interpupillary distance (PD), which is the distance between the centres of the pupils, and the boxed lens size, which refers to the horizontal and vertical dimensions of the lens. Additionally, the rule measures the distance between lenses, the boxed centre distance, and the joint size, which is the overall length of the charniers.
Other important measurements that can be taken with the ABDO Rule include the crest height, which is the height of the bridge of the frame, and the bridge projection, which is the distance from the midpoint of the bridge to the back plane of the front. The rule also measures the distance between rims at specific points below the crest, the bridge height, and the bridge width
The ABDO Rule is designed for ease of use, with clear markings and guidelines to ensure accurate measurements. It is made from durable materials to withstand regular use in a clinical setting. This tool is indispensable for ensuring that eyeglasses are properly fitted to the patient’s face, providing both comfort and optimal vision correction
This Rule is a fundamental instrument for dispensing opticians, facilitating precise measurements that are crucial for the accurate fitting and dispensing of eyeglasses. Its comprehensive design and essential role in ophthalmic dispensing education underscore its importance in the field.
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