Although i wrote several times about eye glasses there is a lot to say
Lets start with practical points
1)Children rarely seek glasses because they do not know how to complain. Parents should test their children at 4-5 years to detect amblyopia. It is more likely for kids to present with headache or recurrent chalazia or problems with near work as hypermetropia is more common in this age than myopia.
2)Children must have a CYCLOPLEGIC autoref.
3)Low asymptomatic hypermetropia up to +3.0 can be left alone if asymptomatic. Symptoms must be CLEARLY related to near work.
4)Generally you do not need to do subjective refraction in children, give +1.0-+2.0 for first time hyperopes and full autoref for myopes.
5)Next age of presentation is school myopia 13-18 and this is easy and straightforward.
6)People between 25 and 40 should not seek glasses otherwise they should have a reason as new work or preparing a higher degree, do take visual complains at this age range more seriously.
7)Above 40 reading becomes increasingly difficult, myopes take off their glasses when reading while hypermetropes suffer optically and psychologically having never worn glasses. Generally at this age i give the far correction of hypermetrope for reading so that after a couple of years he uses these as distance and gets new reading add.
8)I said some general rules
-Avoid cylinders for first time above 20, if necessary undercorrect by 50%.
-Do not increase reading glasses by more than 1.0 D otherwise convergence will suffer.
-Myopes getting glasses first time above 25 should have reduction of 1D/7D.
-Let hyperopes use their accommodation in order not to be glasses dependent.
-Many Lasik myopes after correction complain of near work because ciliary muscle is weak, it recovers in few weeks but be careful with overcorrection.
-Astigmatism deserves a separate post.