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Optical Glossary
The Isolani Optical Glossary brings together the key terms relating to vision, lenses, treatments, light and the technologies that characterise the Isolani Experience. It is a resource designed to help people understand the optical solutions available at Isolani Optical Centres, exclusively within the field of optical retail.
The Glossary is integrated with the Isolani Experience Services, which help people choose the most suitable optical solutions. A range of video podcast dedicated to the main topics relating to vision, providing a clear and accessible in-depth exploration of each subject covered.
Visual impairments
- Short-sightedness - Difficulty seeing things from a distance.
- Hyperopia - Difficulty seeing up close.
- Astigmatism - Focus irregularities in all directions.
- Presbyopia - A decline in the ability to focus on close-up objects as we get older.
- Refractive error - Presence of a visual impairment (short-sightedness, long-sightedness, astigmatism).
- Emmetropia - An eye with no visual impairments; natural vision.
- Anisometropia - Difference in dioptric power between the two eyes.
- Diplopia - Perception of two images of the same object.
- Low vision - Significant reduction in residual vision.
Visual functions and coordination
- Binocular vision - Integration of images from both eyes.
- Convergence - A coordinated inward movement of the eyes.
- Accommodation - Adjusting the focus to different distances.
- Eye dominance - A natural preference for a leading eye.
- Stereopsis - Perception of depth.
- Field of view - The total area that can be taken in without moving one's eyes.
- Peripheral vision - Lateral, rather than central, perception.
- Central vision - Perception of detail in the fovea.
- Night vision - The ability to see in low light.
- Colour vision - Ability to distinguish colours.
- Visual contrast - The ability to distinguish objects that resemble the background.
- Contrast sensitivity - The ability to perceive differences in brightness.
- Colour perception - The ability to distinguish between shades and colour differences.
- Visual acuity - Ability to distinguish image detail and sharpness.
- Visual resolution - The ability to distinguish very fine details.
Light, luminance and light perception
- Adaptation to light - The eye's ability to cope with changes in light.
- Glare - Reduced sharpness in bright light.
- Reflection - Light that is scattered across the surface of the lens.
- Light transmission - The percentage of light that passes through a lens.
- Light absorption - The amount of light absorbed by a lens.
- Absorption category - Classification of sunglasses (Cat. 0-4).
- Transmittance - The percentage of light that passes through a lens (T%).
Optical parameters and measurements
- Dioptre - A unit of measurement for the power of ophthalmic lenses.
- Prism - Controlled refraction of light in ophthalmic lenses.
- Cylinder - Correction of visual abnormalities in ophthalmic lenses.
- Axis - Orientation of the cylindrical correction in ophthalmic lenses.
- Addition - Power difference for near vision in multifocal lenses.
- Equivalent power - The combination of the sphere and the cylinder in ophthalmic lenses.
- Base Curve - Lens curvature and compatibility with the frame.
- Lens thickness - Aesthetics, comfort and technical specifications.
Lens materials and geometry
- Organic materials - Lightweight, durable and safe lenses.
- Mineral materials - Scratch-resistant lenses of high optical quality.
- Refractive index - The ability of a material to deflect light.
- Lens geometry - The optical shape that determines visual performance.
- Aspheric lenses - A more natural view and thinner lenses.
- High-index lenses - Thinner, lighter lenses for high prescriptions.
- Free-form lenses - Digital surface customisation.
Lens treatments
- Anti-reflective coating - Reduced glare and greater transparency.
- Hardening treatment - Protection against scratches.
- Water-repellent treatment - Water repellency.
- Oleophobic coating - Repels fingerprints, grease and oily residues.
- Antistatic treatment - Dust reduction.
- Multi-layer treatment - Comprehensive, multi-layered protection.
- Mirror finish - Visual comfort and style in sunglasses.
- Blue light filter - Digital comfort and picture quality.
Types of ophthalmic lenses
- Single-vision lenses - Correction for a single distance.
- Progressive lenses - Natural vision at all distances.
- Office lenses - Optimal vision for work and indoor environments.
- Lenses for digital use - Eye comfort for computers and smartphones.
- Children's lenses - Safety, comfort and the management of short-sightedness.
- Lenses for driving - Clear visibility and driving comfort.
- Sports lenses - Colours, contrast and visual performance.
- Photochromic lenses - Automatic adjustment to light conditions.
- Polarised lenses - Visual comfort, colours and performance in sport.
Contact lenses
- Contact lenses - Types, materials and advanced contact lens practice.
- Soft contact lenses - Comfort, materials and main uses.
Sunglasses and light management
- Sunglasses - Visual comfort, categories and technologies.
- Mirror finish - Reduced brightness and style.
- Absorption category - Classification of sunglasses (0-4).
- Transmittance - The percentage of light that passes through the lens.
Isolani Experience and in-depth features
The Isolani Optical Glossary complements the programmes and services dedicated to vision, helping people to enjoy a comprehensive and informed experience.
- Advanced Contact Lens Practice - A guide to choosing and looking after contact lenses.
- Behavioural Centring - Measurement of actual lens usage parameters.
- Simulation Room - Testing lenses in real-world conditions.
- Bespoke glasses - Full customisation of the frames and lenses.
- Isolani Podcast - Audio features exploring topics related to vision.
How to use this glossary
Each term is explained clearly and accessibly, with the aim of guiding you through your experience at Isolani Optical Centres and helping you understand the vision solutions available. The glossary is regularly updated and expanded to provide an increasingly comprehensive and reliable reference.
The definitions contained in the Isolani Optical Glossary are provided for information purposes only and relate to the field of optics and the optical industry. They do not contain any medical, clinical or diagnostic information.