> I would bet that if this two-year old were the
> daughter of some of these ODs -- they
> would do a lot more checking before
> they put their child into a -10 diopter lens.

> In fact I do believe that some children have
> an adverse reaction to these drugs, that
> "freeze" the accommodation at the
> maximum "near" position of -10 diopters.

> But let us say that some second-opinion
> optometrists would suggest "holding off"
> on plunging a child that age
> into a -10 diopter lens.

> Good question.
> There are Snellens that have pictures. By these means
> an estimate of visual acuity can be obtained.
> I would bet that if this two-year old were the
> daughter of some of these ODs -- they
> would do a lot more checking before
> they put their child into a -10 diopter lens.
> In fact I do believe that some children have
> an adverse reaction to these drugs, that
> "freeze" the accommodation at the
> maximum "near" position of -10 diopters.
> But let us say that some second-opinion
> optometrists would suggest "holding off"
> on plunging a child that age
> into a -10 diopter lens.
> Second-opinions vary on this subject.
> Otis
> Salmon Egg wrote:
> > On 12/29/06 7:41 AM, in article
> > 1167406898.484719.25500[at]i12g2000cwa.googlegroups.com, "otisbrown[at]pa.net"
> > <otisbrown[at]pa.net> wrote:
> > > > For instance, one 2 year-old had a Snellen of
> > > 20/60 -- which is functional for a child of that age -- and
> > > a retinoscope/cycloplegic of -11 diopters.
> > > How can you even rely upon a 2 year-old to read a Snellen chart correctly?
> > > Bill
> > -- Fermez le Bush

> On 12/29/06 7:41 AM, in article
> 1167406898.484719.25500[at]i12g2000cwa.googlegroups.com, "otisbrown[at]pa.net"
> <otisbrown[at]pa.net> wrote:
> > For instance, one 2 year-old had a Snellen of
> > 20/60 -- which is functional for a child of that age -- and
> > a retinoscope/cycloplegic of -11 diopters.
> How can you even rely upon a 2 year-old to read a Snellen chart correctly?
> Bill
> -- Fermez le Bush

> In article <QN2dnWfu16wm-AjYnZ2dnUVZ_o-knZ2d[at]giganews.com> ,
> "Mike Tyner" <mtyner[at]mindspring.com> wrote:
> > <otisbrown[at]pa.net> wrote
> > > > In fact there are two DIFFERENT methods of judging
> > > a person's refractive STATE.
> > > Yes but your two "methods" don't really address her question, do they?
> > > She is asking why you can't predict VA from refraction.
> My wife was a chemist. Her boss was also. He wanted a formula to
> convert volume into weight. She couldn't do that.

> In article <QN2dnWfu16wm-AjYnZ2dnUVZ_o-knZ2d[at]giganews.com> ,
> "Mike Tyner" <mtyner[at]mindspring.com> wrote:
> > <otisbrown[at]pa.net> wrote
> > > > In fact there are two DIFFERENT methods of judging
> > > a person's refractive STATE.
> > Yes but your two "methods" don't really address her question, do they?
> > > She is asking why you can't predict VA from refraction.
> My wife was a chemist. Her boss was also. He wanted a formula to
> convert volume into weight. She couldn't do that.

> <otisbrown[at]pa.net> wrote
> > In fact there are two DIFFERENT methods of judging
> > a person's refractive STATE.
> Yes but your two "methods" don't really address her question, do they?
> She is asking why you can't predict VA from refraction.

> I have noticed for a long time that my distance vision, which is corrected
> with glasses, is degraded when driving at night. Is the above the
> explanation for that? If so how can one compensate for the problem -
> different prescriptions for day and night use?

> are too weak or when they don't have them. Similarly, flip on the
> overhead lighting and the pupils constrict, giving better acuity. Turn
> all lights off, and they do worse.

> This is why you see myopes squinting a lot when their glasses
> are too weak or when they don't have them

> Take the pinhole away and they'd be lucky to get 20/200.