Illumination, Reading Distance,Computer

Illumination, Reading Distance,Computer
Work Versus Reading Text in a Book

It is surprising that there are only studies from
chickens to determine whether ambient illuminance
has an effect on myopia development. It
was found that refractive errors imposed by spectacle
lenses are similarly compensated over a wide
range of illuminances (see Sect. 1.2.3). Therefore,
these experiments provide no evidence that reading
at low light may represent a risk factor. Only
Feldkaemper et al. [10] have studied whether reduction
of retinal image brightness by covering
the eyes with neutral density filters can induce
deprivation myopia. Refractive development was
not altered if the filters attenuated the ambient
light (illuminance 400 lux) by less than 2 log units.
With darker filters, however, the refractions became
more myopic, although not as myopic as
with frosted eye occluders that degraded the retinal
image, but attenuated light only by 0.38 log
units. Furthermore, when the animals were
placed in dim light (2.0 log units lower than controls)
they did not become myopic without eye
occluders but,even “clear”filters (denoted as “1”in
caused some myopia. These results suggest
that eye growth becomes more sensitive to
minor image degradation when the retinal image
brightness is reduced

A possible reason why this could happen is
that both retinal image brightness and retinal
image contrast and sharpness reduce the release
of dopamine in the retina [10], and dopamine release
has been shown to have an inhibitory effect
on eye growth [47]. Even though these observations
are from chickens, they suggest that
reading (which also represents a minor image
degradation due to the lag of accommodation)
might be more myopigenic at poor illumination.

Can Animal Models Help to Improve the Management of Myopia in Children?

Lowering the retinal image brightness in the
chick eye by light neutral density filters has no effect on
refractive development as long as the filters are weak (1
no attenuation, 2 0.5 log units, 3 1.0 log units). If the filters
are more dense (4 2.0 log units attenuation) some
myopia develops, similar to when the filters are completely
black (5).However, frosted diffusers that attenuate
the light only a little (0.38 log units) cause much
more myopia (6). This result suggests that low retinal
image brightness interferes with eye growth. Furthermore,
if the chicks are kept in low light (2.0 log units
less than controls), even clear occluders cause some
myopia,suggesting that eye growth

Reference on Medicinal plants Part I
Reference on Ayurveda treatments, Principles, Yoga and Health Articles

Reference on Indian medicinal plants and its treatments.