How to choose spectacles ?
how to choose one's optical spectacles ?
- for remote vision :
for wandering with spectacles, you must choose unbreakable -plastic- glasses : they are much lighter than genuine glass, and offer a shield to your eyes, if their template is adequate (see grindstone and prickle). One will remark these glasses get scratched : it is right, but if you take care, they last truly long (several years) ; one should never wipe, but wash them, with tepid water and soap, in the morning (during the night, dust falls on them). On the other hand, the opticians propose us efficient "anti-scratch" surface protection.
- for close vision solely :
the best choice is "half-moon" spectacles, which leaves free the superior half-field of vision ; in addition, they are (relatively) cheap. For this type of spectacles, it is logical to choose genuine glass, since the template of the optics is reduced : the advantage is this matter does not get scratched.
Those you can find at cheap price to the chemist, the jeweler, or in supermarkets are definitely cheaper than in an optician's shop, but their quality is much poorer : if you see twice with them, or if you catch a headache, you will not have made a bargain ! so, trust the professional (the optician) ; on the other hand, when one becomes presbyopic (around 45 years), one needs absolutely consult the ophthalmologist, mainly for detecting the sneaky chronic glaucoma.
- bifocals or varyfocals ?
bifocals came first ; varyfocals are definitely a progress for presbyopia (>45 years old), when one needs glasses both for far and close vision. They are more esthetical, since the optical "step" disappears, and also more convenient, for they provide a certain half distance vision.
Habituation to varyfocals is easy and rapid, subject to the precision of their prescription, and the understanding of their functioning and limits.
how to choose one's solar spectacles ?
- for one who wears spectacles continuously :
# colored optical glasses
this solution is expensive, especially when one is prebyopic, and constrain to change one's frame
# photosensitive glasses
darken and clear up depending luminosity :
elegant and not too expensive solution, which has becomen efficient for numerous years ; sometimes they take a little while to clear up ...
# plates that one clips on corrective glasses :
some are even articulated with a small hinge which is possible to raise like a visor ; personally, I find this convenient
# the "surlunettes"
which encompass the frame and therefore protect from the side luminosity : rather comfortable, but little discreet ! fine for skiing
- for all :
# the essential criterion is the impact resistance : the glass must be organic, thus unbreakable
# organic glass by itself filters more than 95% of ultraviolet rays : it is not the tint which protects the eyes. Paradoxically, it is acquired that organic plain glasses better protect the eyes than mineral dark glasses, behind which the pupils, by reflex, dilate and let irradiate the lens and the retina !
# the choice of the hue is only a question of taste ; but the grey tint is the only one which does not modify the quality of colors (the colour spectrum)
# a simple visor effectively protects not only one's eyes, but also one's face, against the irradiation of the sun, thus prevents skin cancer.
my personal tastes :
# I have always chosen French-made glasses, simply because their optical quality is excellent,
# and prefer them relatively large, for better protective effect, and also for a wider visual field (the heights of my current glasses for my two pairs are 38 mm)
# I do not like "frames without frame", where branches are fixed directly to glasses ; because I find them fragile and unstable. Crosswind glasses adversely affect the visual comfort, especially for strong or progressive glasses, since the shift of the lenses provokes a prismatic effect
# so to ensure stable and light glasses, I recommend an upper stiff armature (U shape, seen from above), on which glasses can be fastened by a simple nylon thread (invisible and solid), which does not restrict inferior visual field.
If you have 2 (even 3) pair of glasses, carry the one that you do not wear in a good rigid box, that would "pop" when you close it, and not a kind of sleeping bag closed by two bad blades !:-)
"you want to save a nail, you loose a horse"
Thanks to Gino Cormier, optician in Madeleine Islands, who helped me for this translation.