Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Sivaraman, Viswanathan; Rizwana, Jameel H.; Ramani, Krishnakumar; Price, Holly; Calver, Richard; Pardhan, Shahina; Vasudevan, Balamurali; Allen, Peter M. (2015)
Languages: English
Types: Article
PURPOSE:\ud \ud The aim was to determine the characteristics of near work-induced transient myopia (NITM) in asymptomatic Indian subjects and the influence of target size and contrast.\ud METHODS:\ud \ud Two studies were conducted: First, 24 myopes and 24 emmetropes viewed four targets (N8 and N12 with 50 and 90 per cent contrasts) placed at 0.2 m for five minutes. The refractive status was assessed objectively, before and after carrying out the near task, with the Grand Seiko WAM-5500 open-field autorefractor under monocular viewing conditions. Second, a different group of 24 myopes and 24 emmetropes viewed a N12 target with 90 per cent contrast for 60 minutes with pre- and post-refractive state measurements repeated as above. NITM was defined as the difference between pre-task and post-task distance refraction.\ud RESULTS:\ud \ud In the first study, myopes demonstrated an initial post-task myopic shift of 0.21 D, whereas emmetropes demonstrated a small hyperopic shift of 0.07 D (p < 0.001). The myopes demonstrated a decay time constant of 6.07 seconds. There was no effect of target size or contrast on the magnitude of the NITM or the decay time constant (p > 0.05). In the second study, myopes showed a NITM of 0.31 D, which was significantly greater than emmetropes (p < 0.001). The myopes demonstrated a decay time constant of 8.16 seconds.\ud CONCLUSION:\ud \ud The magnitude of the NITM was higher in myopes compared to emmetropes for both five minute and 60 minute viewing time. The NITM decayed slightly faster than that found in previous literature for some other ethnic groups. Potential reasons for these findings are discussed.

Share - Bookmark

Cite this article