Glasses
Glasses (also known as eyeglasses or spectacles), are frames containing lenses that are worn in front of the eyes. Besides their use in vision correction, glasses may be worn for eye protection against physical objects (especially safety glasses), or visible light and near-visible radiation (especially sunglasses, which may preclude some damage from ultraviolet, or UV, radiation, and also allow better vision in the presence of bright visible light). They may also be worn for aesthetic reasons, or for specialized viewing purposes (e.g., stereoscopic glasses).
Physics in vision correction
In perfect (20/20) vision, images of the visual world are received by the eye as light waves, which enter the eye through the lens, and stimulate the retina. The image will be inversed, and the brain reinterprets the stimulus to produce what we understand is 'what we see'. For individuals requiring glasses for vision correction, the resultant image may be blurred or out of focus because of the shape of their lenses.
Glasses can correct this by providing a secondary lens that alter the direction of light waves through the shape and density of its glass, resulting in the retina being able to receive the visual input at the same quality as 20/20 vision.
Psychological effects
Experiments have related eyeglasses wearing to lower somatic (bodily) self-esteem [1]. It has been suggested[2] that children who require visual correctives internalize a negative "spectacle image"[3] that is created by the adult world, and propagated by the media.
However, another explanation for the negative self-image for eyeglass wearers is that the eyeglasses themselves are the problem: by altering the appearance of the wearer's eyes, the eyeglasses obscure important nonverbal communication. Eyeglass wearers may learn through simple reinforcement to avoid the gaze of others since the information communicated by their eyes might appear to be at odds with their verbal message. This process may begin as soon as the wearing of eyeglasses begins: it has been found that infant vocalizations were elicited when an adult brought their face close, but only if their eyes were not obscured by dark eyeglasses[4]. This hypothesis may also explain why people wearing eyeglasses are judged by others to have very prominent eyes[5], while the wearers themselves tend to de-emphasize the importance of their eyes in their appearance[6].
References
- ↑ Veldman, D.J. (1970). Correlates of visual acuity in college freshmen. Perceptual and Motor Skills 30: 551-558.
- ↑ Terry, R.L., and L.A. Stockton. (1993). Eyeglasses and children's schemata. Journal of Social Psychology 133: 425-438.
- ↑ Terry, R.L. (1990). Social and personality effects of vision correctives. Journal of Social Behavior and Personality 5: 683-696.
- ↑ Bloom, K. (1974). Eye contact as a setting event for infant learning. Journal of Experimental Child Psychology 17: 250-263.
- ↑ McKelvie, S.J. (1997). Perception of faces with and without spectacles. Perceptual and Motor Skills 84: 497-498.
- ↑ Terry, R.L., and C.S. Brady. (1976). Effects of framed spectacles and contact lenses on self-ratings of facial attractiveness. Perceptual and Motor Skills 42: 789-790.