Yes, sunglasses are indeed a type of glasses.
Understanding the Definition of Sunglasses
Sunglasses are primarily designed to protect the eyes from bright sunlight and harmful ultraviolet (UV) radiation. They achieve this through darkened lenses that filter light. While they share a basic structural similarity with eyeglasses, the primary function of sunglasses is light management rather than vision correction. According to the reference:
They are usually made of a plastic or metal frame and two lenses that are darkened to filter out light.
Key Similarities and Differences
While both sunglasses and eyeglasses are glasses that involve a frame and lenses, here's a breakdown of their key differences:
Similarities:
- Frame and Lenses: Both sunglasses and eyeglasses consist of a frame that holds lenses.
- Structure: Both types of glasses use a similar design to sit on the face.
Differences:
- Primary Function: Eyeglasses are primarily for vision correction (nearsightedness, farsightedness, astigmatism). Sunglasses are mainly for reducing light intensity.
- Lens Function: Sunglasses typically have darkened lenses. Eyeglasses can be clear or tinted and might have specific corrective features.
- Prescription: Sunglasses can have prescription lenses, according to the reference, but they can also be non-prescription. Eyeglasses always have prescription lenses.
Practical Insights
- Prescription Sunglasses: These combine the functions of both types of glasses and correct vision while filtering light.
- Non-Prescription Sunglasses: These serve only to shield the eyes from light and do not alter vision.
- Shades: The term "shades" is often used as an informal way to refer to sunglasses.
- Material: Frames are commonly made from plastic or metal, as noted in the reference.
- Purpose: Sunglasses and eyeglasses may have very different purposes, but they're both types of glasses.
Summary
Sunglasses are a specific type of glasses characterized by their dark lenses and primary function of light filtering. While they can have prescription lenses like eyeglasses, they are generally used for protection and comfort rather than vision correction alone. Both sunglasses and eyeglasses fall under the broader category of eyewear.
