The accommodative response, refractive error and mental effort: 1. The sympathetic nervous system

✍ Scribed by Mark A. Bullimore; Bernard Gilmartin

• Book ID: 104650156
• Publisher: Springer-Verlag
• Year: 1988
• Tongue: English
• Weight: 705 KB
• Volume: 69
• Category: Article
• ISSN: 0012-4486
• DOI: 10.1007/bf00162751

✦ Synopsis

The accommodative response of 12 emmetropic subjects was measured for an array of numbers located at -1,-3 and -5 dioptres using an objective infra-red optometer. Responses were compared for passive (reading numbers) and active (adding numbers) conditions. The imposition of mental effort induced a significant increase in mean response for the -1 D stimulus, a response equivalent to the passive condition at -3 D and a reduction in response at -5 D. Mental effort induced similar responses for the -1 D and -3 D locations when sympathetic innervation to .the ciliary muscle was blocked with the beta-receptor antagonist timolol maleate. Responses for the -5 D location were, however, significantly increased. It is proposed that sympathetic inhibition can modify the effect of mental effort on near accommodative responses.