• The scatter of the differential light threshold has a short-term and a long-term component. Although these components are significantly positively correlated, the relationship is not strong enough to accurately predict in an individual patient the long-term fluctuation from the short-term fluctuation. The reversible variation of the retinal sensitivity with time is statistically related to the temporal variation of the short-term scatter, to the variation in reaction time, and probably to the variation in the intraocular pressure.
Flammer J, Drance SM, Schulzer M. Covariates of the Long-term Fluctuation of the Differential Light Threshold. Arch Ophthalmol. 1984;102(6):880-882. doi:10.1001/archopht.1984.01040030700022